Oliver Kahn says Bayern Munich "absolutely have to stop" allowing opposing teams back into games after they nearly squandered another lead in the 4-2 Champions League win at Viktoria Plzen.

Goals from Sadio Mane and Thomas Muller, as well as a Leon Goretzka double had Bayern four goals up and cruising at half-time against the Czech champions.

But two second-half strikes from Plzen led to worries Bayern would let another advantage slip, after conceding a 95th-minute Anthony Modeste equaliser in the 2-2 Bundesliga draw with Borussia Dortmund at the weekend having led 2-0.

Julian Nagelsmann's side held on this time for three points to secure their place in the knockout stages, but Bayern CEO Kahn remains worried over their ability to see out games.

"Four games, four wins and into the round of 16," Kahn posted on Twitter. "A compliment to the team, in this group that was not a matter of course.

"After a furious first half, we let the opponent come back into the game.

"We absolutely have to stop this!"

Inter have a chance to become the first Italian side to ever beat Barcelona twice in a Champions League campaign when they meet at Camp Nou on Wednesday.

Meanwhile, Club Brugge are on the brink of their first trip to the knockout stages as they play Atletico Madrid.

Mohamed Salah can make history with one more Champions League goal for Liverpool on their trip to Scotland to take on Rangers, and Bayern Munich are one win away from their own record as they try to win an 11th consecutive group stage match.

Tottenham will look to break out of a scoring slump when they host Eintracht Frankfurt, while Porto and Bayer Leverkusen are battling it out in Group B.

With plenty of important matchups, Stats Perform has parsed through the data to preview the eight fixtures on Wednesday and shine a light on some of the more interesting angles.

Barcelona v Inter

Inter's 1-0 victory against Barcelona at San Siro last week was their first triumph over the Spanish giants since April 2010, with Barca collecting four wins and one draw since.

With another win, Inter can become the first Italian side to ever beat Barcelona twice in the same Champions League campaign, although they have lost all five of their away fixtures at Camp Nou – their most losses at any away venue in the competition.

In fact, Camp Nou has not been a happy hunting ground for Italian sides in general, with a 3-0 victory for Juventus in 2020 marking the country's only win at the venue in the last 17 tries (L13 D3).

It is not just Barcelona who have given Inter trouble on away days, with their last away win in the Champions League against a Spanish opponent coming back in 2004 against Valencia.

Working in Inter's favour is road warrior Lautaro Martinez, who has scored six of his seven Champions League goals away from home.

Tottenham v Eintracht Frankfurt

After banking four consecutive wins against Borussia Dortmund between 2017 and 2019, Tottenham are now winless in their past five Champions League fixtures against German sides (D1 L4).

On the other side, Eintracht have enjoyed success when travelling to England in European competition, winning both of their previous two attempts – against Arsenal in 2019, and West Ham in April this year – in the Europa League.

However, this is a clear step up from the Europa League, and after winning their first ever Champions League away game last month (1-0 at Marseille), Frankfurt will be looking to become the only German team to ever win their first two away fixtures in the competition.

The 0-0 draw between these two sides in Frankfurt a week ago was the second consecutive Champions League game where Tottenham have failed to score a goal – also losing 2-0 to Sporting. The last time they went three games in the competition without scoring was back in 2011.

Striker Harry Kane will be key, as he boasts the best minutes-per-goal figure – 20 goals in 27 appearances for a goal every 118 minutes – of any English player with at least 10 goals in the Champions League.

Atletico Madrid v Club Brugge

Not many, if any, would have tipped Club Brugge to top Group B ahead of Atletico Madrid, Bayer Leverkusen and Porto, but they have defeated all three to lead with a perfect nine points and zero goals conceded.

One more win for Brugge would see them progress past the group stage for the first time, in their 10th Champions League campaign. By defeating Atletico, they would become the first Belgian side since Anderlecht in 2000 to win four games in a row in the competition.

Brugge are also one goal away from matching their highest goal tally from a single Champions League campaign, with eight goals in 2020-21.

Surprisingly, Atletico have struggled at home in the Champions League, snapping a streak of eight games without a win (D5 L3) by defeating Porto this season.

Brugge's Ferran Jutgla has registered a goal and an assist in each of his past two Champions League games, and if he can manage to do it again, he will join Robert Lewandowski and Leroy Sane as the only players since 2003-04 to have a goal and an assist in three straight games in the competition.

Bayer Leverkusen v Porto

With Brugge seemingly cruising, Porto, Leverkusen and Atletico are likely fighting it out for one automatic qualification spot, and Leverkusen will feel good about their chances as Porto are winless in their last seven away games against German teams (D2 L5).

After defeating Atletico at home on the second matchday, Leverkusen will be looking to win consecutive Champions League home fixtures in the same campaign for the first time since 2014.

Patrick Schick is Leverkusen's focal point going forward, attempting more than twice as many shots (12) as any of his team-mates this Champions League season, but he is yet to score, having missed a penalty against Porto in last week's 2-0 loss.

Porto's Mehdi Taremi assisted both goals in the reverse fixture, marking the first time he has been involved in multiple goals in a Champions League game, while the sending-off of Jeremie Frimpong gave Leverkusen their 11th red card in their history in the competition, trailing only Bayern Munich (21) amongst German sides.

Other fixtures:

Napoli v Ajax

5 – Napoli beat Ajax 6-1 in the reverse fixture at Johan Cruyff Arena, with the five-goal margin marking the heaviest defeat Ajax have ever suffered in European competition.

10 – With one more win, Napoli would become the fourth Italian club to ever mount a 10-game unbeaten streak in the Champions League, with six wins and three draws from their past nine fixtures.

Rangers v Liverpool

5 – Rangers have failed to score in their past five European games against English competition, including a 2-0 loss against Liverpool last week.

35 – Mohamed Salah has scored 35 Champions League goals for Liverpool – only Didier Droga (36 for Chelsea) and Sergio Aguero (36 for Manchester City) have scored more for a single Premier League club in the competition.

Sporting v Marseille

9 – Marseille have lost their past nine away fixtures in the Champions League, and with one more loss they would become the sixth team to ever post 10 consecutive away defeats in the competition, and the first from France.

18 – It has been 18 years since Sporting lost a home fixture against a French side in European competition, with that loss coming against Sochaux in the 2004 UEFA Cup.

Viktoria Plzen v Bayern Munich

31 – Bayern Munich are undefeated in their past 31 Champions League group stage matches (28W 3D) – which is an all-time high – and with one more win they will set the new record for consecutive group stage wins with 11.

32 – Viktoria Plzen have faced 32 shots on target in their first three games of this Champions League campaign – more than any other side. In the reverse fixture, Bayern had 13 shots on target.

Julian Nagelsmann feels Bayern Munich's resounding 5-0 win over Viktoria Plzen was "another step in the right direction" for his side ahead of facing Borussia Dortmund.

Bayern followed up Friday's 4-0 Bundesliga thrashing of Bayer Leverkusen with an even more emphatic victory in Tuesday's Champions League tie with Czech champions Plzen.

It marks the first time the Bavarians have won back-to-back matches in all competitions since August, having gone four league games without a win prior to the international break.

Nagelsmann is pleased with what he saw from his side against Plzen, with Bayern returning to form at just the right time ahead of Saturday's Klassiker showdown with fierce rivals Dortmund.

"The boys did well today," Nagelsmann told DAZN. "That's how you have to approach a game. We decided it quickly then controlled it. 

"With a view to Saturday, that was important, serious and well deserved. It was another game that shows we are taking steps in the right direction."

The hosts were three goals up inside 21 minutes, with Serge Gnabry and Sadio Mane netting after Leroy Sane had opened the scoring at the Allianz Arena.

Sane doubled his tally early in the second half before substitute Eric Choupo-Moting rounded off the scoring for the leaders in a one-sided Group C contest.

It is the 26th time Bayern have scored five or more goals in a Champions League match, which is five more than next-best Barcelona.

Mane wasted some promising chances to add to the scoring, netting from just one of his six attempts, but the forward was happy with his side's performance.

"The team played a great game, with a lot of chances created," he said. "We deserved to win. 

"The past few weeks have been tough. It was important we reacted. We reacted well after the international break. Hopefully we can continue like this until the end of the season.

"We have nine points from three Champions League games and a good goal difference. We are in a good place. 

"We were disciplined today. We were well prepared for the opponent and that's where most of the goals came from."

Bayern have now gone 31 games without defeat in the group stage of the Champions League, overtaking the record of 30 set by Real Madrid in 2017.

"We rightly received criticism during the international break," said Leon Goretzka, who set up two of the goals against Plzen.

"We used the time well and focused on our game again. Our aim is to perform on a regular basis. We're still extremely upset about the games before that."

Julian Nagelsmann may shuffle his pack for Bayern Munich's Champions League game against Viktoria Plzen on Tuesday, with the depleted Bavarians set to host Borussia Dortmund four days later.

Bayern have started their Champions League campaign with back-to-back wins over Inter and Barcelona, and lead the duo by three points at the top of Group C.

Should they record another European win at the Allianz Arena next time out, Bayern will have won their first three Champions League matches for a fourth season in succession.

On the domestic stage, however, Bayern trail surprise pace-setters Union Berlin and Freiburg after an inconsistent run of results, and host rivals Dortmund on Saturday.

With Thomas Muller and Joshua Kimmich set to miss the Plzen match after contracting COVID-19, Nagelsmann is aware of the need to manage his squad.

"We need to rotate because of Joshua and Thomas, so there are different ways, there are so many options," Nagelsmann said at his pre-match press conference.

"You'll see tomorrow which I decide. We're still in a situation where we need to grab points. 

"It's important for the Champions League to win the game against Plzen, and also to keep the rhythm for the game against Dortmund, where there might be more pressure than in the Champions League.

"Plzen like to play defensively and counter-attack, and that could be a challenge. We'll try to get into our optimum phase considering what is still ahead."

Bayern have been heavily impacted by COVID-19 recently, with Manuel Neuer and Leon Goretzka withdrawing from the Germany squad after contracting the virus last month.

Nagelsmann offered a positive update on the conditions of Muller and Kimmich, and hopes to have them back after Tuesday's match, adding: "Thomas and Joshua don't have any symptoms, they're doing well. Of course, they would love to play, but nothing has changed.

"We can do the tests on Friday and if those go well, they are candidates against Dortmund. It depends on the tests we will do.

"In general, the incidence is high in Munich so it's a factor that concerns us. We've talked with the players. 

"They've had the suggestion that they're not going to go to the Oktoberfest since the officials took part, so no partying there!

"Outside of the pitch, professional players are normal people. Everybody's looking after themselves."

Nagelsmann also revealed Kingsley Coman will not feature against Plzen despite recovering from a muscle injury, but said Serge Gnabry had his full support if selected to start out wide.

"First of all, with Kingsley, he is doing well," Nagelsmann said. "He practiced well, he was great, but he's not going to be a part of tomorrow's game.

"We'll try to heighten that [his condition] in the next couple of days and then he's an option against Dortmund, but he's not going to start, that's for sure.

"He is doing well. I have good expectations that he can fill a position in the squad against Dortmund, it would be great to have him, and not so great for the opponent.

"I haven't decided 100 per cent, but Serge is certainly a candidate there. We have to see also what we will do against Dortmund, and what happens with Thomas.

"I've known Serge for ages and I think a lot of him. He doesn't worry too much on the field and plays freely. We have a good connection with each other."

Bayern Munich pair Thomas Muller and Joshua Kimmich have gone into isolation after testing positive to COVID-19.

The German champions announced the news on Saturday, with Muller and Kimmich having both been in the starting XI for Friday's 4-0 Bundesliga win over Bayer Leverkusen.

Bayern said the pair had tested positive on Saturday, were asymptomatic, doing well and isolating at their respective homes.

The Bundesliga outfit are due to face Czech club Viktoria Plzen in the Champions League at Allianz Arena on Tuesday.

The positive tests come after Bayern pair Manuel Neuer and Leon Goretzka were withdrawn from Germany camp last week after their own infections.

Kimmich has started every game in all competitions this season for Bayern, netting two goals and providing four assists.

Muller has started all bar one of Bayern's games in all competitions, scoring twice and providing four assists.

Champions League football resumes on Tuesday, with Robert Lewandowski's return to Bayern Munich with Barcelona being an obvious highlight.

Barcelona travel to Bavaria in a match few would be disappointed to see replicated in next year's final, with Atletico Madrid also travelling to Germany to take on Bayer Leverkusen.

After Premier League football was suspended at the weekend as a mark of respect following the death of the Queen, Liverpool are back in action against Ajax and are seeking to respond to a defeat to Napoli last week, while Tottenham travel to face Sporting CP.

Elsewhere, Inter face Viktoria Plzen after both sides lost their opening fixture and Eintracht Frankfurt, following defeat to Sporting, travel to Marseille – and the only remaining match of the day is Porto against Brugge.

For a closer look at all the action you can look forward to, Stats Perform has dived into the Opta data to highlight the most interesting facts for each match.

Bayern vs Barcelona

Scoring a hat-trick on his Champions League debut for Barcelona against Viktoria Plzen, Lewandowski returns to Bavaria with a devastating record this season and his goals in the 5-1 triumph saw Barcelona scoring more in one game than they had in their previous nine matches in the competition (4).

While that will give the visitors confidence, Barcelona have a poor record against the Bundesliga champions having suffered eight defeats in the competition to Bayern – twice as many as they have lost against any other opponent (4 vs Milan, Chelsea and PSG).

Four of those losses have come in the group stages, with Bayern winning both matches in 1998-99 and 2021-22 to boast a 100 per cent record against Barcelona in that regard, who have not lost more than twice against any other opponent in the group stage.

On top of that, Bayern have won 35 of their last 37 home matches in the group stages of the Champions League – the only exceptions being a 3-2 defeat to Manchester City in December 2013 and a 1-1 draw with Ajax in October 2018.

Liverpool vs Ajax

Liverpool won both meetings with Ajax in the 2020-21 Champions League group stages, the only campaign in the competition when they have met, with the Dutch side not beating Liverpool in any competition since a 5-1 win in December 1966.

Ajax's defeat to Liverpool in December 2020 is one of only two defeats that the Eredivisie champions have experienced in their last 25 matches (W13, D10) away from home in UEFA competition, the other being a 2-0 defeat to Getafe in February 2020 in the Europa League.

Having suffered defeat to Napoli last week, Liverpool are looking to avoid back-to-back defeats to start a Champions League campaign for the first time, while they have only lost their first home match in two of their previous 46 major European campaigns (W35, D9).

With seven Champions League wins in a row, Ajax travel to Anfield with a stellar run in the competition as only Bayern (8) boast a better winning streak currently.

Sporting vs Tottenham

While the two sides have never met competitively, Sporting are winless in all six of their Champions League matches against English opposition (D1, L5) and have lost all three of those games in Lisbon without scoring a single goal.

Tottenham's record against Portuguese opponents is scarce, winning against Pacos de Ferreira in the qualifying phases for the 2021-22 Europa League but not facing an opponent from the country in the Europe's premier competition since a 4-3 aggregate defeat to Benfica in the 1962-63 semi-final.

Sporting have never won their opening two matches in the Champions League, while Antonio Conte is looking to follow in the footsteps of Mauricio Pochettino as Spurs seek back-to-back wins to open a Champions League campaign for the first time since 2017-18 season under the Argentine.

Bayer Leverkusen vs Atletico

Neither side has a particularly good record to encourage them heading into Tuesday's tie, with Leverkusen having won just four of their last 20 Champions League matches (D8, L8), while Atletico have only kept one clean sheet in 21 away matches against German opposition in major UEFA competitions.

Atletico have only won one of four away matches against Leverkusen, a 4-2 victory in February 2017 in the Champions League, and have won only one of their last seven matches in Germany – though that was the match in 2017.

Late drama is to be expected whenever Atletico compete in the Champions League, with five of their last 10 goals in the competition coming in the 90th minute of matches.

Other fixtures:

Viktoria Plzen vs Inter

8 - Viktoria Plzen have won their last eight home European matches (including qualifiers), scoring at least twice in every win (21 in total). They have only lost one of their last 19 on home soil in European football (W16 D2), a 5-0 reverse against Real Madrid during their last UEFA Champions League campaign in November 2018.

2 - Since the start of the 2020-21 campaign, Inter striker Lautaro Martínez has scored just two goals from 48 shots (inc. blocks) in the UEFA Champions League. The Argentine’s shot conversion rate of 4.2 per cent (including blocks) is the lowest of any player to have attempted 30+ shots during this period.

Porto vs Brugge

3 - Porto have lost their last three UEFA Champions League matches, with two of those coming against Atletico; they have never lost four in a row in the competition before.

1 - In major European competition, Club Brugge have lost five of their six away matches in Portugal (W1), their one win coming against Sporting Braga in September 2011 in the UEFA Europa League.

Marseille vs Eintracht Frankfurt

15 - Marseille have lost 15 of their last 16 UEFA Champions League matches (W1), with the exception coming in their last home game in the competition in December 2020 against Olympiacos.

2 - Marseille and Eintracht Frankfurt will face in European competition for only the second time, also meeting in the 2018-19 UEFA Europa League group stages. Frankfurt won both matches (2-1 away, 4-0 home).

Benfica eased through to the Champions League group stage with a 5-0 aggregate thrashing of Dynamo Kyiv on Tuesday, while Maccabi Haifa and Viktoria Plzen also qualified.

The three teams will now look ahead to the draw on Thursday when they will find out who they will be facing in the group stage.

Last season's quarter-finalists Benfica built on an impressive 2-0 first-leg victory against a rusty Kyiv side with first-half goals from Nicolas Otamendi, Rafa Silva and David Neres essentially killing the tie by half-time at Estadio da Luz.

Meanwhile, Haifa scored late on to earn a thrilling 5-4 aggregate comeback win over Red Star Belgrade in Serbia to reach their first Champions League group stage since the 2009-10 season.

A 90th-minute own goal from Red Star striker Milan Pavkov was enough to progress the Israeli side, who had been 2-0 down on the night after winning the home leg 3-2.

Haifa will be joined in Thursday's draw by Plzen, who also advanced after coming from behind to beat Qarabag 2-1 on aggregate.

A first-half goal from Filip Ozobic had put the Azerbaijani side in front after a goalless first leg, but Jan Kopic and Jan Kliment bagged after the interval to turn the game around and get their team into the group stage of the competition for the first time since the 2018-19 campaign.