Former Villarreal star Robert Pires believes Liverpool are "the best team in Europe", but insists the Yellow Submarine can overturn a 2-0 first-leg deficit to reach the Champions League final.

After a routine Liverpool win at Anfield last Wednesday, Villarreal will attempt to become just the second team to overturn a two-goal first-leg deficit in a Champions League semi-final (after Liverpool's 4-3 aggregate win over Barcelona in 2019).

Villarreal did not manage a single shot on target in their away reverse, but Pires' former club did win their only previous home game against Liverpool in European competition (a 1-0 win in 2015-16's Europa League semi-finals).

Although Pires said quadruple-chasing Liverpool are the best team on the continent, he does not think the result is a foregone conclusion on Tuesday.

"Of course Villarreal can go through," he said in comments reported by AS. "We know how complicated it is, we cannot deny that. We know the level of Liverpool and their quality, they are very good and very strong, but Villarreal has not said the last word.

"For me, Liverpool is the best in Europe at the moment and that makes it a great challenge. For this reason, Villarreal, which is a very solid team, suffered a lot in the first leg. But they came out alive, and knowing Emery and the quality of this team, I wouldn't be comfortable.

"To that they must add a bit of luck, we know that these comebacks must have that point of fortune to turn the tie around. I tell people that if the player feels that the fans are with you and push, anything is possible. 

"Hopefully Villarreal will reach the final in Paris. That is my wish, I would very much like it to be."

Villarreal have never lost a home match in the Champions League knockout stages, although they have drawn five of their seven such fixtures.

Before Pires joined the Yellow Submarine, for whom he made 131 total appearances across four seasons, he lined up as an opposition player for the club's only previous Champions League semi-final appearance, with Arsenal.

The Gunners reached the final with a 1-0 aggregate win after clinging onto a goalless draw in Spain, with Jens Lehmann saving Juan Roman Riquelme's late penalty, and Pires said his memories of that contest make him believe Villarreal will provide Liverpool with a stern test.

"This team is not eliminated, far from it," he added. "I played the other semi-final with Arsenal and we also had an advantage, so we hoped to get through without suffering. And the reality was very different.

"We suffered like dogs in that game. We came from eliminating Juventus and Madrid, we were very confident and secure, but we arrived here and had a really bad time. I don't know what happened to us, but it was the game in which we suffered the most of all. 

"That's why I think Villarreal can give Liverpool a cane. I know, I've lived it."

Villarreal are unbeaten in 12 home matches in all competitions, winning eight, and recorded an incredible 1-0 success against Bayern Munich in their last home Champions League outing.

Real Madrid and Villarreal have it all to do when they host Manchester City and Liverpool respectively in the second legs of their Champions League semi-final ties in midweek.

Fresh off the back of winning a second LaLiga title in three seasons, Madrid are aiming to overturn a 4-3 deficit against City following last week's thrilling first leg in Manchester.

That was the joint-highest scoring semi-final first leg in the competition's history, along with Liverpool 5-2 Roma in 2017-18, and more drama awaits in the Spanish capital.

Villarreal face an even bigger task, meanwhile, as they trail Liverpool 2-0 through an unfortunate Pervis Estupinan own goal and a Sadio Mane strike at Anfield.

However, only once before have the Reds won both legs of a knockout stage tie against Spanish opposition in the Champions League or its former guise as the European Cup.

So will it be an all-English final in Paris on May 28, or can the LaLiga pair turn things around on home turf?

Ahead of the second legs, Stats Perform digs into some of the best Opta numbers around the two semi-final ties.

Villarreal v Liverpool

To put the size of Villarreal's task into some perspective, only once before – Liverpool versus Barcelona in 2019 – has a team overturned a two-goal first-leg deficit at this stage of the Champions League.

Villarreal are unbeaten at home in Champions League knockout ties, albeit having won just two of their seven such games. The bad news, though, is that across those seven matches, neither side has managed to score more than once on any occasion.

If they are to have any hope of advancing then Unai Emery's men need to display far more attacking impetus than was on show last week, having attempted only one shot and failed to hit the target at Anfield. The last team to fail to record a shot on target across two legs of a Champions League semi-final was Deportivo de La Coruna in 2003-04, against Jose Mourinho's Porto.

Should Liverpool see the job through, they will become only the fourth side to reach the final of the European Cup/ Champions League on 10 or more occasions after Real Madrid (16), Bayern Munich and Milan (both 11), with their current tally of nine the most of any English side.

Jurgen Klopp's side have been formidable on the road in Europe this season, scoring 15 goals and conceding five across their five away Champions League matches, all of which have ended in victory. Should they win on Tuesday, they will boast the longest 100 per cent away record by any team in a single European Cup or Champions League campaign.

After netting in the first leg it is likely that Mane will again be selected in Liverpool's star-studded front three. The Senegal international has scored 14 knockout-stage goals for the Reds in the Champions League, leaving him one short of Chelsea legend Frank Lampard's record for the most for an English club.

Real Madrid v Manchester City

The omens are good for City as they have progressed from nine of their previous 10 knockout ties in the Champions League after winning the first leg, the only exception being against Monaco at the last-16 stage in 2016-17 after squandering a 5-3 advantage to lose 6-6 on away goals.

Madrid have been eliminated from all five previous Champions League semi-finals in which they have lost the first leg, meanwhile, though they have advanced from two of their past three knockout ties when losing the first leg – against Wolfsburg in the 2015-16 quarter-finals and versus Paris Saint-Germain in this season's last 16.

Los Blancos, the competition's most successful side, have lost their past two Champions League games, though only once before have they lost three on the spin. Head coach Carlo Ancelotti, incidentally, has never lost three in a row with this his 178th match.

A draw would be enough to see City through, but they have won their last three matches against Madrid in the Champions League and could become the third side to win four in a row against them in UEFA's showpiece competition, the only previous sides to have done so being Ajax (between 1973 and 1995) and Bayern Munich (between 2000 and 2002).

City boss Pep Guardiola has had his fair share of battles with Madrid down the years, not least in the Champions League. The Catalan coach has won four matches against Los Blancos in the competition – only Ottmar Hitzfeld (seven) has won more – with half of those wins coming at the Santiago Bernabeu.

Karim Benzema has rescued Madrid a number of times in Europe this season, the Frenchman having netted nine times in the knockout stage alone. Only former team-mate Cristiano Ronaldo (10) has ever scored more in a single season, while Benzema could become the fourth player to score in both legs of the quarter-finals and semi-finals in a single season after Fernando Morientes (2003-04), Neymar (2014-15) and Edin Dzeko (2017-18). 

While Benzema has rightly received plenty of plaudits, strike partner Vinicius Junior has himself played a huge part in Madrid's charge for a record-extending 14th European Cup. The 28 open-play chances created by the Brazil international is the most of any player in the Champions League since Dusan Tadic (36) in 2018-19.

Trent Alexander-Arnold knows Liverpool must not be complacent when they start the second leg of their Champions League semi-final against Villarreal on Tuesday with a "dangerous" 2-0 lead.

Jurgen Klopp's side are strong favourites to face Manchester City or Real Madrid in the final at the Stade de France after a Pervis Estupinan own goal and Sadio Mane's strike at Anfield last week put them in command

Liverpool are the only side to reach the final after losing the first leg of a semi-final by two goals or more, overturning a 3-0 deficit with a sensational 4-0 victory over Barcelona three years ago.

The Reds are unbeaten in 12 matches and make the trip to El Madrigal on a five-game winning streak - keeping clean sheets in their past four victories.

Alexander-Arnold says they will not arrive in Spain thinking it is already job done as they prepare to face a side that dumped Juventus and Bayern Munich out.

The full-back said: "Anything can happen in football, they're a top-quality side who can beat world-class teams.

"We've seen that with Juve and Bayern. They play up to the underdog so we cannot get complacent. An old cliche, only half-time. Next goal is vital in this tie."

Liverpool boss Jurgen Klopp insists the Reds still have work to do to secure a spot in the Champions League final, and expects Villarreal to try "with all they have" in Tuesday's semi-final second leg.

The Reds are still chasing a historic quadruple after beating the Yellow Submarine 2-0 in last week's first leg at Anfield, with goals from Andrew Robertson and Sadio Mane putting Klopp's team on the brink of a third Champions League final during his seven-year tenure.

Klopp's team produced a dominant performance at Anfield to restrict Villarreal to no attempts on target, and could become the first team since Porto in 2003-04 (against Deportivo La Coruna) to not concede a single shot on target across a two-legged Champions League semi-final.

Liverpool also recorded 22 high turnovers as they suffocated Unai Emery's team, the most by a team in a Champions League knockout game this season and the most Klopp's Reds have ever produced in the competition.

However, Klopp insisted his team would have to withstand a fierce Villarreal response on Tuesday, and said Liverpool would not take anything for granted.

"No [the tie is not over], we know that. It's half-time. In the best possible way, we ignore the result from the first game," Klopp told his pre-match press conference.

"As if it was a cup tie with only one leg and it would be decided in Villarreal, we will try to win there, that's what we want to try, knowing that they will go with all they have, that was clear with all the things Unai said after the game.

"It will be another tough one, but it's fine, the Champions League semi-final should be tough. We never expected it to be easy and this will not be easy. We played a good game at home, and we had better play a good game there as well.

"The Champions League semi-final is the second-most important game you can play [after the final]. That's why whatever happened in the last few weeks is not important.

"You never know if you will reach the semi-final again, if you will ever have another chance to go to the final, you never know. We have an exceptional team here, but nothing is taken for granted, you better treat it carefully and be ready, and we will be ready."

Liverpool have won on all five of their Champions League road trips this season. Should Klopp's side win in Spain, they would have played the most away games while maintaining a 100 per cent record by any team in a single European Cup/Champions League campaign.

With the Reds on a 13-match unbeaten streak on their travels in all competitions, Klopp highlighted the importance of having extra options available in his squad compared to previous seasons.

"In general, our last periods of the season are pretty intense, because the Premier League is so difficult," Klopp added.

"It helps that we know, historically we are in the best possible shape [physically], where we don't have to push the boys through like we did in 2018, where we arrived at the final [a 3-1 loss to Real Madrid] pretty much on three wheels, with players coming back from injury and these kinds of things.

"We have to make sure we can make changes here and there and keep them all in rhythm, and to win the football games, that's what it's about."

Tuesday will also see midfielder Thiago Alcantara return to Spain after an outstanding first-leg display in which he attempted over 100 passes, and Klopp said the in-form 31-year-old would start for any team in world football.

"When Thiago is in the shape he is in now, he would play in each team in the world, and he would perform for Spain as well," he added. "He had problems when he arrived here, he got injured, and Spain obviously has a lot of options in midfield because it's an incredibly talented football team.

"But in the shape he's in at the moment he would play for each national team, and not only play in it, he would probably be the outstanding performer. 

"Every person needs to be fit and to gain rhythm and then he can show his best football. If he's in the right place physically, he will show everyone how good he is."

Villarreal boss Unai Emery says his side are excited to pit themselves against "the best team in the world" in Liverpool, as they try to overcome a two-goal deficit in the Champions League semi-finals.

The Yellow Submarine enter Tuesday's decisive second leg against Jurgen Klopp's men 2-0 down after the first meeting at Anfield last Wednesday.

To reach the final in Paris, Villarreal must become only the second team to overturn a two-goal first-leg deficit in a Champions League semi-final after Liverpool did so in 2018-19, losing 3-0 to Barcelona at Camp Nou before recording an incredible 4-0 home triumph.

But Villarreal struggled against Klopp's in-form Reds last week, attempting just one shot and failing to hit the target, and they could become the first team since 2003-04 (Deportivo La Coruna against FC Porto) to fail to record a shot on target across two legs of a Champions League semi-final tie.

Having previously described Klopp's outfit as the "best-ever" Liverpool team, Emery has now labelled them the finest side in world football, but insisted his players are relishing the prospect of competing with the Reds.

"We are very excited. The favourites were better at their stadium, but we managed to defend well," Emery said. 

"The team is psyched up to play our match and have our chances against the best team in the world. To live this moment, with all our people and against a rival, and passing this test would be excellent. I don't know if we'll be able to."

Emery is no stranger to thrilling Champions League comebacks, having been on the receiving end of one of the most famous turnarounds in history when his Paris Saint-Germain lost 6-1 at Barcelona after winning the first leg 4-0 in 2016-17's last-16.

However, the former Arsenal boss said a lot of things have changed since that classic contest, highlighting that neither team would benefit from the scrapped away goals rule on Tuesday.

"A lot of things change from the game against PSG against Barca, even things that are not in our hands. It does not favour [either team] that there is no longer the double value of away goals," he added.

"The first thing that changes is that we play at La Ceramica with our fans. We have to win, but we have to play a brutal defensive game and find our game from there."

In reaching the Champions League semi-finals for the second time in their history (the other in 2005-06), Villarreal have relied on a strong home record: Emery's men are unbeaten in seven home knockout games in the competition's history, although five of those ended level.

After Villarreal's 1-0 home win over Bayern Munich helped them dump the German champions out of the competition in the quarter-finals, defender Pau Torres says that success can serve as an inspiration for the hosts. 

"The game against Bayern can serve as an example. They were favourites and we managed to subdue them in our stadium," Torres said. "We are aware of what is at stake and what needs to be done. We have our game plan. We have seen a very strong Villarreal in important games.

"The objective is only one, no matter how it is achieved. We know that the game is long. A goal puts us in the tie.

"The coach has told us to be ourselves. We are preparing very well for the tie. We are going to be able to see a very recognisable Villarreal, with whom we all feel identified."

Jurgen Klopp insisted Liverpool still have it all to do in the second leg of their Champions League semi-final against Villarreal, despite the first leg ending in a convincing 2-0 win.

The Reds carved out their advantage during a two-minute second-half spell that saw Pervis Estupinan put through his own net and Sadio Mane get on the scoresheet.

The visitors managed just a single shot across the 90 minutes, one which failed even to test Alisson in the Reds' goal.

However, Klopp is taking nothing for granted ahead of the return leg in Spain next week, saying at a media conference after the game: "The full work is [left] to do. Nothing happened yet. 

"You play a game and it's 2-0 at half-time, you have to be completely on alert, you have to be 100 per cent in the right mood, you have the play the second half like you played the first. 

"There's nothing to defend, if you do that you give all the advantages you might have had away immediately. 

"We know we go there and it will be a tricky atmosphere for us, different to tonight. 

"Those players, you saw it tonight, they fight for the coach with all they have. What I like was that everybody could see that we fight with all we have and it's always the same. 

"If they beat us with a result that brings them to the final then they deserve it and, if not, then we deserve it. That's how the competition is."

Liverpool had taken 12 shots without scoring in an opening period that saw Villarreal frustrate - a theme of their march to this stage of the competition. 

But Klopp did not ask his team to change things up during the half-time break, instead asking for more of the same from his players.

He added: "We spoke at half-time, I thought we looked really fresh in the first half and had good legs. 

"It's intense for us to play the way we play but it's intense for the opponent to defend us in that way as well.

"It was the challenge, how it is for all human beings, when you try and you fail and try and fail [not to] think, 'Come on, it's not my day!' 

"We really had to stay positive and try and fail, try and fail, and keep trying. And that's what we did."

Liverpool left back Andrew Robertson said he and his team-mates are "enjoying" their hectic schedule as they earned a 2-0 first leg lead in their Champions League semi-final against Villarreal.

An own goal and a Sadio Mane strike, both early in the second half, was enough for Jurgen Klopp's men to secure a decent cushion ahead of next Tuesday's second leg in Spain.

Villarreal frustrated Liverpool at Anfield in the first half, but were unable to stop them from winning their ninth Champions League match of the season, the most games the Reds have ever won in a single campaign in European competition (excluding qualifiers).

Speaking to BT Sport after the win, captain Jordan Henderson praised the visitors, and said staying "positive" was key for Liverpool.

"Yeah, very organised team," Henderson said about Unai Emery's side. "We knew they'd make it difficult, but it was important that we just kept going, stay positive and we had the confidence that if we did that, kept moving the ball quickly, we'd eventually break them down, and we did that with two good goals."

It was Henderson's cross that deflected in off Pervis Estupinan to finally break the deadlock, and when told it had deflected, the England international jokingly replied: "Did it? I thought it went straight in!

"Yeah a little bit lucky, but it was good play, good build up... But, you need a little bit of luck against teams with a low block. We got that with the first and thankfully we got another one."

Liverpool had 19 shots to Villarreal's one on a dominant night for the Reds. The Yellow Submarine's one shot, which missed the target, is the joint-fewest by any side in a Champions League semi-final according to Opta since this data has been available (2003-04), along with Inter v Barcelona in 2009-10.

Robertson was also asked by BT Sport about the game, and he was keen to point out that the players are enjoying themselves, with an unprecedented quadruple of the Premier League, Champions League, FA Cup and EFL Cup still possible.

"We had quite a few chances in the first half, just trying to break them down and keep doing what we were doing," the Scotland captain said. "The first goal always kind of does that [gives you a boost], we then had a bit of momentum. The noise in here was incredible after the first goal and that kind of took us to the second one.

"We'd have liked to add maybe one more, it wasn't meant to be but a clean sheet and two goals? We can't argue with that.

"You have to [work hard], it's the semi-final of the Champions League. If you can't run about for 90 minutes in this kind of game then when will you?

"Our intensity's been really high the last couple of games, we've had a real hectic schedule and we're enjoying it. I think you seen that today.

"There's still a lot of work to do in this tie, but we're happy with our work tonight."

Also asked about not getting frustrated by a stubborn Villarreal defence, Robertson added: "That was the message from Hendo at half-time, just saying we were playing well first half, probably some of the best we've played and we didn't get a goal for it, but we kept going, kept trying to be patient and luckily with a big deflection (smiling at Henderson), we managed to get the breakthrough."

After 45 minutes of this Champions League semi-final first leg, the travelling Villarreal fans had every reason to believe they might be witnessing another miracle.

Their team had made it to half-time in the cauldron of Anfield having kept the score at 0-0, and they had also - at times - made a quadruple-chasing Liverpool look short of ideas.

As such, thoughts will no doubt have turned to the recent shock wins over Juventus and Bayern Munich, and the possibility of taking another major scalp back to Castellon.

Unfortunately, any supporter in yellow thinking along those lines had not accounted for the fact that, even among Europe's elite clubs, there are levels.

And, although Manchester City might have a strong case to be ranked alongside them, Liverpool are otherwise alone at the summit. 

It did not look much like that during an opening period that ended with the hosts having taken 12 shots, the most in a Champions League semi-final first half without scoring since such data was first collected in 2003-04.

That owed much to Villarreal's sheer refusal to offer up quality chances, with the midfield and defence working beautifully in tandem to deny all space.

The dark arts were also being deployed impressively, goalkeeper Geronimo Rulli taking as much time as he could over goal kicks, while cheap fouls were bought from frustrated opponents.

However, as he proved during Sunday's Merseyside derby win over Everton, Jurgen Klopp is never better than when given a half-time puzzle to solve.

And it looked from the very first whistle of the second period that the German had repeated the trick once again.

Suddenly, there was an extra zip to Liverpool's play, and their visitors' previously solid shape was beginning to look porous as players were dragged out against their will.

Admittedly, there was an element of fortune to the Reds' opener, Pervis Estupinan's attempted block looping over a stranded Rulli and into the back of the net.

But it had been earned through a rapid left-to-right passing exchange that opened space for Jordan Henderson to cross - the sort of move that had been missing in the first half.

From there, Liverpool smelled blood, and just two minutes later had put together another slick pattern to leave a rattled Villarreal two down. 

It was a whirlwind attacking flurry that so few teams can produce, one that will have given Klopp confidence that a third Champions League final appearance with this club awaits.

As impressive as their route to this stage of the tournament has been, Villarreal never trailed either Juventus or Bayern by more than a single goal at any stage of those ties.

And it is hard to imagine how they might close that deficit in Spain next week without opening up too much against such deadly opponents. 

Stranger things have happened, of course, but the likelihood is that a meeting with a Liverpool team eyeing the history books will prove to be a step too far for Villarreal. 

Liverpool are in the driving seat of their Champions League semi-final against Villarreal after a 2-0 win at Anfield on Wednesday.

A game that was never likely to match the excitement of Tuesday's seven-goal thriller between Manchester City and Real Madrid finally came to life in the second half as an own goal from Pervis Estupinan and a Sadio Mane strike sealed a strong first-leg advantage for the Reds.

Unai Emery's side defended resolutely for much of the game, managing to get to half-time goalless, but they were ultimately undone by some typically fast attacking from Jurgen Klopp's team in the second half.

This was Liverpool's 12th European Cup or Champions League semi-final, with no English side playing in the final four more often (level with Manchester United), and was also the first time the Reds have played in the semi-finals of the EFL Cup, FA Cup and European Cup in the same campaign, and it was that experience of the big occasion that ultimately shone through.

It was a tentative start from the home side, though Mane will have expected to do better with a header when found by a neat cross from Mohamed Salah early on with the Senegalese forward directing his effort wide.

Thiago Alcantara came as close as anyone to breaking the deadlock in the first half with a shot from almost 30 yards that crashed against the left-hand post, but the visitors did a good job of frustrating the Premier League side in the opening 45 minutes.

An electric beginning to the second half from Klopp's side finally saw them take the lead in the 53rd minute, with Jordan Henderson's cross from the right taking a fortunate deflection off the foot of Estupinan and flying past Rulli at his near post.

Another arrived just two minutes later as a good passing move ended with Salah sliding a ball through to Mane, who prodded under the goalkeeper to make it 2-0 to the Reds.

The Yellow Submarine avoided further damage but have it all to do when the two meet again in the second leg at the El Madrigal next Tuesday.

What does it mean? Liverpool show patience to break through, again

Liverpool finally overcame a determined Everton in the Merseyside derby on Sunday, it was said to be perfect preparation for Villarreal, who were always going to come to Anfield to frustrate in the first leg.

That proved to be the case as, like with the Toffees, Villarreal kept Liverpool at bay in the first half, running down the clock, blocking all attacks and keeping their net unbothered.

However, the relentless Reds again managed to force a couple of second half goals, having had 19 shots in all, facing just one solitary effort from the visitors.

Thiago once again shines in the middle

The former Barcelona and Bayern Munich midfielder has been purring in Liverpool's midfield in recent games, and he was on form again here as he helped to dissect a stubborn opposition.

Thiago completed 99 of 103 passes (96.1 per cent), enjoying a fantastic pass completion percentage in the opposition's half of 94.1 from 68 attempts. He also made more interceptions than anyone (five) and gained possession 10 times in all.

More English misery for Yellow Submarine

Emery's men put up a brave fight but eventually succumbed to a strong and determined Liverpool team, and it maintained a poor record for Villarreal in England.

Since a 2-1 victory on Merseyside against Everton in August 2005, Villarreal have not managed to win any of their last nine away games in England in all competitions (drawn three, lost six), having also tasted defeat at Manchester United in the group stages earlier this season.

What’s next?

Liverpool travel to Newcastle United on Saturday as they resume their title chase in the Premier League, while Villarreal are away to Deportivo Alaves on the same day.

The former Barcelona and Bayern Munich midfielder has been purring in Liverpool's midfield in recent games, and he was on form again here as he helped to dissect a stubborn opposition.

Jurgen Klopp has made three changes to his starting line-up for Liverpool's Champions League semi-final first leg against Villarreal.

With his side having claimed a 2-0 Merseyside derby victory over Everton last time out, the German has looked to freshen things up in defence, midfield and attack.

As has become customary during two-game weeks this season, Ibrahima Konate comes into the centre of defence to replace Joel Matip.

In the centre of the park, the captain Jordan Henderson takes the place of Naby Keita.

And up top, January signing Luis Diaz joins Sadio Mane and Mohamed Salah, with Diogo Jota dropping to the bench.

Roberto Firmino is not among the substitutes as he recovers from injury, while Curtis Jones and Kostas Tsimikas are both out with illness.

Liverpool: Alisson, Alexander-Arnold, Konate, Van Dijk, Robertson, Fabinho, Thiago, Henderson, Salah, Mane, Diaz.

Liverpool welcome Villarreal to Anfield on Wednesday and are heavy favourites in their Champions League semi-final tie.

Under Jurgen Klopp, the Reds have become one of the world's best teams. They have reached two Champions League finals, winning their sixth title in the competition in 2019, and followed that up with a maiden Premier League crown a year later. This season, their eyes are fixed firmly on an unprecedented quadruple – the EFL Cup is already theirs, they will face Chelsea in an FA Cup showdown next month and their race in the league with Manchester City is set to go to the wire.

Standing in Liverpool's way of a final against Manchester City or Real Madrid are, however, Unai Emery's Villarreal. While the Yellow Submarine will be considered underdogs, the reigning Europa League champions will be no pushovers.

Liverpool were frustrated for just over an hour by their relegation-threatened local rivals Everton in the Merseyside derby on Sunday, until Andy Robertson headed home and Divock Origi settled matters late on. They should be anticipating a similar test on Wednesday.

Yet whereas Everton are devoid of confidence or quality, Villarreal have both in abundance. They have already overcome European heavyweights in the form of Juventus and Bayern Munich, and will have home advantage in the second leg. They averaged just 35 per cent of possession across the two legs against the Bundesliga giants.

The last time these semi-finalists met was in the last four of the 2015-16 Europa League, and the two legs of this tie will come just a day under six years after each match in that previous fixture. Back in 2016, matters were rather different for Liverpool, who progressed 3-1 on aggregate, but went on to lose in the final to a Sevilla side coached by Emery.

It is fitting, then, that as Liverpool bid for European glory once more, a team that stood in the way of their first continental final under Klopp will try to prevent the Reds reaching a fourth with the German at the helm.

A remarkable turnaround

A quick glance at the team that started in the second leg of that 2016 tie, which Liverpool won 3-0 at Anfield, tells you the transformation that the Reds have gone through under Klopp has been dramatic.

Simon Mignolet started in goal, behind a back four of Nathaniel Clyne, the now-retired Kolo Toure, Dejan Lovren and Alberto Moreno (who might have been facing his former club for Villarreal if not for a serious knee injury sustained last month). Roberto Firmino and James Milner started, but they are the only two of that 18-strong squad that remain at Liverpool, and neither can be considered regular starters anymore.

Liverpool were convincing winners – racking up an xG of 3.8, producing 25 shots with 12 of those on target.

The team that take to the field on Wednesday will almost certainly feature a world-class goalkeeper in Alisson, one of Europe's best defenders in Virgil van Dijk, a Champions League-winning midfielder in Thiago Alcantara, two exceptional full-backs and, of course, a devilishly potent attacking trident, whichever three of Mohamed Salah, Sadio Mane, Diogo Jota or Luis Diaz line up. Firmino is unavailable.

Salah has returned to goalscoring form in timely fashion, after a relative dry spell. Only in 2017-18 (10) has he scored more Champions League goals in a single campaign than the eight he has netted this season, moving his tally for the club to 33. He is now just three behind both Didier Drogba and Sergio Aguero for the most goals scored in the competition for an English side.

For Klopp to take that Liverpool team back in 2015-16 to two finals (they lost on penalties in the EFL Cup to Manchester City that year) was, looking back, an extraordinary achievement, especially considering he only took over in October.

Since then, they have gone from strength to strength. In the Premier League, Klopp has won 162 of his 253 games (64 per cent), with his team scoring a remarkable 544 goals, and the German has averaged 2.15 points per game. He is building a true dynasty.

Emery to have his say?

"Unai's a world-class coach and is doing an incredible job," said Klopp in his pre-match news conference on Tuesday. And he is right, Emery – perhaps unfairly maligned during his stints at Arsenal and Paris Saint-Germain – has been brilliant for Villarreal.

He could well have left for cash-rich Newcastle United earlier this season but elected to stay put, and Villarreal are, at least in Europe, reaping the rewards. Their shoot-out success against Manchester United in last season's Europa League final represented Emery's fourth triumph in UEFA's second-tier tournament, and he also took Arsenal to the final in 2018-19, losing to Chelsea.

Villarreal are not flying quite as high in LaLiga, though surely that can be forgiven. They sit seventh, having won their last two games, and still have hope of qualifying for European competition through the league, too.

Emery has taken on Klopp five times as a coach, winning the first meeting – that Europa League final back in 2016.

Klopp claimed victory in two of the three Premier League encounters with the Spaniard's Arsenal, with those victories being 5-1 and 3-1 respectively. The other league match was drawn 1-1, while Liverpool also beat Arsenal on penalties in the 2019-20 EFL Cup after a wild 5-5 draw.

Emery can feel hard done by that he was not given more time at PSG. His win percentage of 76 was the best of any coach during the QSI era, putting him above the likes of Carlo Ancelotti (64) and Thomas Tuchel (75). He succeeded in 87 of his 114 matches in charge and claimed seven trophies. Only Laurent Blanc (11) has won more silverware at PSG since 2011, while Emery's team scored 2.7 goals per game, with just Tuchel managing to match that.

Yet Emery's ability to get a side competing way beyond their expected level is what he is renowned for. His run of three successive Europa League titles with Sevilla was extraordinary, and he seems to be in a similar position at Villarreal.

Having to rebuild his reputation slightly after his spell at Arsenal, Emery has won 51 of 104 matches in all competitions (49 per cent), with Villarreal scoring 188 goals and conceding 101, keeping 37 clean sheets.

Emery's win percentage has not been beaten by any other Villarreal coach to have taken charge of 100 matches, while in Gerard Moreno, who has directly contributed to 60 goals during Emery's tenure, the Spanish side have a brilliant striker to call on.

Liverpool have, in many ways, come full circle with this tie, but the Villarreal they will face on this occasion have improved just as much, in relative terms, as Klopp's team have. It is set to be a fascinating tussle.

Unai Emery says Villarreal must try and "surf the wave of experience" they have gained when they do battle with the "best-ever Liverpool" for a place in the Champions League final.

Villarreal dumped out Serie A giants Juventus and Bundesliga champions Bayern Munich on a surprise run to the last four.

The Yellow Submarine travel to Anfield for the first leg on Wednesday plotting to tear up yet another script.

Villarreal beat Manchester United in the Europa League final last season and it would be an incredible story if they won Europe's premier club competition in Seville next month.

Emery rates Premier League title contenders Liverpool, who are eyeing an unprecedented quadruple, as the favourites to lift the trophy and knows his side are no longer a surprise package

The Villarreal head coach said at a pre-match news conference on Tuesday: "We face a bigger challenge than before. The surprise factor is no longer there. They are the number one favourites to win this competition.

"The team is a mirror of their coach, Jurgen Klopp, in terms of playing with joy, with enthusiasm. They are in the best moment.

"I remember my experiences against Liverpool [when he was Arsenal boss] at Anfield as challenging. I recognise the work done and the identity created by Klopp, which has since been further improved.

"I see that as an additional motivation for me, to try and beat the best-ever Liverpool. For that we will need to show our best version."

Emery says the LaLiga side must draw on the experience they have gained from their exploits in Europe.

He added: "We have been able to compete against big teams like Juve and Bayern, so they know it will be a tough game and will have to be 100 per cent and give it all at Anfield.

"Of course they will feel favourites as that is natural. It is an even higher difficulty than Juventus and Bayern Munich.

"We will try to surf the wave of experience we started accumulating last season."

Villarreal have not won in their previous eight matches in England, but their last victory came on Merseyside against Everton in August 2005.

Raul Albiol says reaching the Champions League final with Villarreal "would become a milestone in the history of football" as they prepare to take on Liverpool in the last four.

The Spanish club have already defied the odds by eliminating heavyweights Juventus and Bayern Munich en route to setting up a two-legged showdown with Liverpool.

Villarreal are up against English opponents for the fourth time out of their past five major European semi-final appearances.

That includes a 3-1 aggregate defeat to Liverpool at this stage of the 2015-16 Europa League, and they enter this latest encounter as underdogs despite their impressive run.

While aware of the size of the task that awaits his side, Villarreal skipper Albiol is eager to write his name in club folklore by keeping their European adventure alive.

"It would be a dream to play the Champions League final with Villarreal, a humble and hardworking team that has struggled to remain among the elite," he told UEFA's website.

"A club coming from a town with 50,000 inhabitants making it to the Champions League final would become a milestone in the history of football. 

"So, it would be something that not only Villarreal supporters would remember but many football lovers."

Albiol has won eight trophies at club level across an 18-year career, including the Europa League with Villarreal last season.

That ensured a place in this term's Champions League, and Villarreal have lost just two of their 10 matches thus far.

Reflecting on the past year, Albiol – a member of Spain's 2010 World Cup-winning squad – said: "The Europa League's helped us have these experiences in the Champions League. 

"They are not at the same level, but last year we started to be a competitive team in Europe and to know how to play in tough knockout rounds.

"I think that now, by eliminating Juve and Bayern, we have shown that the team has personality, knows how to suffer; we have come through in difficult moments.

"Winning the club's first European title was historic, but if we suffer defeat to Liverpool, it could be historic too. 

"So, we have to do our best during these two matches to try to do it; we have to give everything to write another chapter in history.

"If Villarreal got into the Champions final, it would be something historic for a club, and a village, such as Villarreal."

Villarreal are winless in their past eight trips to England in European competition, most recently losing 2-1 to Manchester United in the group stage seventh months ago.

Belief is high in the Yellow Submarine's camp, however, having also won back-to-back domestic matches to climb up to seventh in LaLiga.

"It reflects that with effort, dedication and team spirit, you can achieve great things – and that money and great players are not the only way to win titles," Albiol said. 

"In the end, we are a great group of players with a good level, who want to grow and improve, who work hard and spend many hours getting ready for every match with the staff. 

"We are now at that point in which we can believe."

Jurgen Klopp hailed Unai Emery as a "world-class coach" and vowed Liverpool will not underestimate Champions League semi-final opponents Villarreal.

The Reds are still in contention for an unprecedented quadruple and enter Wednesday's first leg with Villarreal at Anfield as strong favourites to advance to next month's final.

However, the Spanish club stunned Juventus in the last 16 and followed that up by eliminating a much-fancied Bayern Munich side in the quarter-finals.

Villarreal's domestic form has improved of late, meanwhile, having won back-to-back LaLiga games – against Getafe and Valencia – to move into seventh place.

Liverpool have progressed from nine of their previous 11 European Cup and Champions League semi-finals, but Klopp is taking nothing for granted against Emery's Villarreal.

"We are here because we got the results we needed," Klopp said at Tuesday's pre-match news conference.

"It's special to be part of the semi-final. It's a massive game. So many coaches and players work their socks off to be close to a semi-final, so we have to cherish it but enjoy it.

"We face a difficult opponent. They are made for this competition. The way they set up is really good.

"They may have had a little advantage where Juve and Bayern maybe underestimated them. That never happens with us, no chance of that. That advantage may have gone.

"They are a good football team that wants to make history. It would be the first time they would make the final, which is massive for them. But for us, it's the same importance."

Emery guided Sevilla to a 3-1 Europa League final win over Klopp's Liverpool in 2016 – one of 11 trophies he has won across an 18-year coaching career.

He took charge of Villarreal in July 2020 following a disappointing stint at Arsenal and guided the Yellow Submarine to Europa League glory last season.

"I have a lot of respect for Unai and Villarreal," Klopp added. "I've analysed them properly, and wow. Impressive.

"Unai is a detailed-obsessed manager who prepared for all different situations in a game. That's what his team executes. Different ways to press and react on different results.

"It's really, really impressive. Unai is a world-class coach and doing an incredible job there. The good thing about the analysis is we're not involved in those games.

"We must make life as difficult for them as possible. That's what we try to do over these two legs."

Liverpool beat Villarreal 3-1 on aggregate in their only previous European encounter, in the 2015-16 Europa League semi-final, with both teams winning their home leg.

Villarreal have not won any of their last eight away games on English soil, a run that includes a 2-1 Champions League group-stage defeat to Manchester United in September.

And Klopp will be looking to take a victory to Estadio de la Ceramica for next week's reverse fixture as Liverpool aim to make it a clean sweep of trophies this season.

"We have two halves to play. We know when we to go Villarreal, it will be an emotional atmosphere," Klopp said. "There are moments where we will suffer tomorrow.

"I know that already and that's what we have to be ready for. There's no need to be nervous, that's how it is. This advantage at home we have to use.

"Whichever result we will get, we will fight with it. It means everything to us to reach the Champions League final."

Mohamed Salah has set his sights on further Champions League and domestic success with Liverpool.

Jurgen Klopp's side face Villarreal in the first leg of their semi-final encounter on Wednesday, just under three years on from their last triumph in the tournament. The Champions League is one of three trophies that Liverpool are still in the hunt for this season, having already won the EFL Cup.

Salah helped Liverpool to victory in an all-English affair against Tottenham on that occasion in 2019, and says he wants to recapture those highs with a second European crown.

"I want to have the feeling again that we had after winning the Champions League," he told the club's matchday programme ahead of the game.

"It was unbelievable and in my mind that's why I want to win it again with Liverpool. The feeling we had in the city when we went on the bus and toured was unbelievable. 

"The Premier League was kind of different because it was not done [due to COVID-19 restrictions], but I want to win the Champions League again and I want to win the Premier League again. 

"That is my target with the team right now."

Salah has enjoyed another prolific campaign at Anfield, and is the leading scorer in the Premier League this season with 22 goals to his name, five ahead of his nearest rival Son Heung-min of Tottenham.

But the forward feels he has more to give than what he has delivered, adding: "I saw my game improving, but the season before last I had 19 goals and 10 assists in the Premier League.

"In my first season it was also 10 assists, so I'm always trying to score goals and give assists. 

"That is always my game and this season I feel a lot of improvement with the ball, but I go back to what I said before. The most important thing is to help this team win trophies and I am trying to help to do that."