Copious injuries, late positive COVID-19 tests and a suspension; a highly anticipated clash between Serie A leaders Milan and defending champions Juventus at San Siro on Wednesday threatened to seriously underwhelm.

There was no Alvaro Morata for the Juve, while full-backs Alex Sandro and Juan Cuadrado were forced to sit out after returning positive coronavirus results.

Milan were without star striker Zlatan Ibrahimovic and their midfield was decimated by the absences of Sandro Tonali (suspension), Ismael Bennacer (injury) and Rade Krunic (coronavirus). The dire situation forced Stefano Pioli to start right-back Davide Calabria alongside Franck Kessie in the central pivot.

Yet despite the difficulties faced by both teams, a thriller was served up in Milan, and Federico Chiesa took centre stage as Milan's unbeaten streak in Serie A was ended at 27 by a 3-1 loss to Juve.

ACT ONE

The last time Milan held a superior position to Juve heading into a meeting of the sides was in November 2015, and on that occasion the Bianconeri emerged triumphant thanks to a goal from Paulo Dybala.

While the Argentina international, who has been struggling for consistency and dealing with a fever, was not the man to open the scoring on this occasion, he still played a pivotal role.

After drifting across the pitch to offer support to Chiesa, he held up a pass from the winger before returning it by dragging the ball back behind his standing leg and flicking it around Alessio Romagnoli.

It was weighted perfectly for Chiesa's dart into the box, which was not tracked adequately by Theo Hernandez, and he drilled a shot across Gianluigi Donnarumma into the bottom-left corner.

ACT TWO

A thoroughly entertaining first half saw Juve control possession but Milan get more shots away. There were 21 in total during the opening 45 minutes, 12 for the Rossoneri and nine for Juve, a number only two Serie A games this season have exceeded (Sassuolo v Cagliari – 22, Cagliari v Napoli – 23).

Wojciech Szczesny kept out Samu Castillejo, Rafael Leao and Hakan Calhanoglu, as well as stopping Aaron Ramsey from scoring what would have been an incredible own goal, before he was finally beaten by the unlikely source of Calabria.

Juve did not appear happy the goal was allowed to stand, with Calhanoglu putting in a contentious challenge on Adrien Rabiot to launch the counter-attack from which Leao fed Calabria to guide a fine finish into the top-right corner.

It ensured Milan found the back of the net for a 36th consecutive Serie A game – a run only bettered by Juve (43 in 2014 and 44 in 2017) – with Leao involved in an eighth goal in 12 league appearances this season, one more than he managed across the entirety of the previous campaign.

ACT THREE

Unsurprisingly the game was far less open after the interval, but Chiesa was able to separate the teams once more.

Again it was Dybala leading the supporting cast, spotting his team-mate in space on the right and drilling a pass across for him to attack Hernandez once more.

Just as in the first half, Chiesa's feet proved too quick as he shifted the ball to his left and threaded a curling shot between Hernandez and Romagnoli and into the bottom-left corner. It was his sixth goal involvement (three scored, three assisted) against Milan in Serie A, which is more than he has managed against any other side.

The 23-year-old is proving himself to be a man for the big occasion. Since the start of last season, he has been thoroughly impressive against the best teams in the league. In that time, he has had a hand in three goals against Milan (two scored, one assisted) and Atalanta (two scored, one assisted) and also scored in meetings with Inter, Napoli and Lazio.

THE UNDERSTUDIES

While Cristiano Ronaldo was arguably the quietest of Juve's forward-thinking players, Chiesa made way for Dejan Kulusevski a minute after his goal, as Weston McKennie entered for Dybala.

The pair combined to put the game to bed in the 76th minute, McKennie sweeping in after a fine run down the right from Kulusevski.

The sole consolation for the Rossoneri was that they remained top of the league due to Inter's defeat to Sampdoria earlier on Tuesday, but Chiesa's blockbuster display proved Juve will not be content with solely being extras in the title race this season.

During Fred's early months in the Premier League, it would be fair to say many Manchester City fans will have felt their team had dodged a bullet.

Prior to his move to the red side of Manchester, speculation was rife that Pep Guardiola had identified Fred – at Shakhtar Donetsk back then – as a long-term replacement for Fernandinho in midfield.

Fred had made a reputation for himself as an effective box-to-box midfielder who could have an impact on the ball as well as off it.

But it was difficult to see what possessed Manchester United to pip City to his reported £55million signing during the 2018-19 season, as he struggled with the tempo of the game and didn't appear to offer anything particularly outstanding to any part of the United unit.

However, as the past year or so – especially this season – highlights, Fred has become one of Ole Gunnar Solskjaer's most-trusted individuals.

As United welcome City to Old Trafford in Wednesday's EFL Cup semi-final, Fred has another chance to show why that is the case.

MR DEPENDABLE?

Fred may have only started 10 of United's 16 Premier League games this term, but a telling pattern emerges when you look at which matches they were.

Among those games, he was in Solskjaer's line-up for outings against Chelsea, Arsenal, Everton, Southampton, City, Leeds United, Leicester City and Aston Villa.

All of those are, of course, either 'big six' rivals or teams pushing to be in the upper echelons of the Premier League this term. He was brought on at half-time in the 6-1 demolition by Tottenham, and while he hardly held Spurs at bay, they were at the very least less rampant in the second half.

It cannot be a coincidence that these are the type of matches Fred has been used in most often, with Solskjaer clearly valuing the midfielder's off-the-ball qualities as United regularly look to absorb pressure and spring counter-attacks.

That will likely be the tactic again as United host EFL Cup holders City in Wednesday's semi-final, a one-legged repeat of last season's two-match tie in the same round.

A year on from the 2019-20 first leg, Solskjaer will be hoping for a rather different outcome, as City – opting to go with a false nine – overran United's midfield and battered them at Old Trafford that day, deservedly winning 3-1.

There will likely be just four players from the United starting XI of the game a year ago who line up on Wednesday, with Fred one of them. The upheaval in the squad has been significant, but it's telling that the Brazilian is one of those still playing a role, and an important one at that.

He may have let himself down again with a red card against Paris Saint-Germain, but it seems Solskjaer accepted responsibility over that incident.

FRED THE FACILITATOR

It seems highly unlikely Fred will ever be in the running for any of the Premier League's end-of-season individual awards – he doesn't score or create enough, and you cannot say his influence is anything like that of N'Golo Kante in the title-winning Leicester City side.

But, one player who surely will be a candidate for individual gongs is Bruno Fernandes, and players like him need colleagues like Fred in order to thrive.

The Brazil international is well-rounded and has the technical ability to lend support in offensive situations, such as his neat interchanges with Paul Pogba against Aston Villa last time out.

But Fred is undoubtedly at his most effective when his side are not in possession, with his 49 tackles more than any other United or City midfielder in all competitions this term.

It's a similar story with his interceptions count. Fred has made 30 in 2020-21, five more than Rodrigo, who ranks second among the United and City engine room players. That is despite Fred despite playing over 400 minutes less than City's Spain international. Of course, City generally have more of the ball than United, but it still highlights Fred's awareness.

Critics might point out his 12 key passes is a rather meagre total, but with Bruno Fernandes (69) creating chances with such frequency, one could argue it doesn't matter – after all, Fred isn't being put in the team to be a creator.

Curiously, in the league since January 1 last year, United actually have a worse win percentage (50) with Fred in the starting XI than they do without him (71.4), though this is clearly skewed by the fact he is often reserved for games against better opposition.

But what is notable from this time period is United concede fewer shots - 10.3 per game - on average when Fred starts. That goes up to 12.1 shots per 90 minutes when he's not in the first XI – while the team's own shots count increases from 12.4 to 15 each game with the Internacional youth product in the side.

Opta's advanced passing data also reflects favourably on Fred, particularly with respect to starting three open-play sequences that ended in a goal, which is the joint second highest in the Premier League this term.

He has also initiated four open-play passing sequences that led to a shot, which only Luke Shaw, Harry Maguire and Fernandes can better in the Red Devils' squad.

UNNOTICED, UNDER-APPRECIATED, BUT NOT USELESS

Fred is perhaps the sort of player many would consider dispensable, and maybe he is in certain matches. Rarely does he stand out as an individual, certainly not to the extent of say Fernandes and Marcus Rashford, and much of his work can go unnoticed.

But many of us inadvertently analyse players in isolation and by their individual numbers, rather than how they fit into the collective. Sure, Fred doesn't create many chances, but what he offers United off the ball is seemingly vital for Solskjaer.

Fred may not be the player a lot of United fans expected two and a half years ago, but he has certainly proven himself to be no dud.

Finally, 2020 is history - there won't be many people who aren't happy to see the back of a difficult year.

While the coronavirus pandemic shows no sign of making a swift exit, the turn of the year at least gives us the chance to look forward, and the same is true in the world of sport.

2020 saw many promising young players make the step up, some undoubtedly down to the absences caused by coronavirus or the packed schedule that the pandemic has led to.

We've picked out 21 under-21 players to keep an eye on in 2021 - and while you may already be familiar with some of them, there's good reason to give them your attention this year...

Illan Meslier, 20 - Leeds United

Few goalkeepers can come away from a 6-2 defeat having impressed, but Meslier did so against Manchester United recently. His eight saves prevented Leeds' crushing loss from getting even more embarrassing, while only three goalkeepers have produced more in a single Premier League match this term. His total of 63 is also the second most in the division – the France Under-21 talent, who joined on a permanent deal from Lorient last year, appears to have a big future ahead of him.

Kristoffer Klaesson, 20 - Valerenga

Goalkeepers tend to break through a little later than outfield players, but Norway youth international Klaesson has already been first-choice at Valerenga for the best part of 16 months – he only turned 20 in November. Coincidentally, he could have become a team-mate of Meslier's in 2020 as Leeds were reportedly interested, but he remains in Norway for the time being.

William Saliba, 19 - Arsenal

Saliba is certainly one of the most recognisable names on this list – after all, he has been owned by Arsenal for getting on for two years. Unfortunately, he has not been afforded much of a chance by Mikel Arteta this term, which makes him an interesting prospect to watch in 2021. Either he'll eventually get an opportunity at the Gunners, or a loan move will provide him with a crack at first-team football. After a tricky 2020, he'll want to get his career back on track.

Perr Schuurs, 21 - Ajax

Given his appearance, playing style and the fact he has come through Ajax's academy, comparisons between Schuurs and Matthijs de Ligt were to be expected. He may not reach the Juventus star's level, but he has certainly shown real promise that is reportedly interesting Liverpool. Schuurs is one of the five youngest players to have featured for at least 500 minutes in this season's Champions League, while his 47 ball recoveries was the sixth highest of any player in the group stage.

Ethan Laird, 19 - Manchester United

Aaron Wan-Bissaka was supposed to fix Man United's issues at right-back, but this season his defensive positioning has been concerning and he appears to have become even less effective in attack – his chances created and open-play crosses per 90 minutes have decreased significantly. Laird has long been considered a fine prospect at United and boasts the technical abilities to be a threat in attack. If he can stay fit, chances could be in the offing.

Tariq Lamptey, 20 - Brighton and Hove Albion

Having joined Brighton last January from Chelsea, Lamptey has quickly made a name for himself as an exciting wing-back. Last year saw the diminutive talent enjoy something of a breakthrough, but in 2021 he'll be looking to truly establish himself and potentially break into the England squad. There are few more exhilarating full-backs in the Premier League – his 3.8 dribbles per game is the third most among defenders to have featured more than twice.

Nuno Mendes, 18 - Sporting CP

Sporting have a wealth of talent coming through at the moment and left-back Mendes is arguably chief among them. Blessed with fine technical abilities, the 18-year-old is apparently a target for Man United, Liverpool and Real Madrid. Already a regular having started 10 of the Primeira Liga leaders' 11 games this term, Mendes' 10 completed dribbles is the fourth-highest among defenders in the division, while his 28 interceptions is second only to team-mate Luis Neto.

Gabriel Menino, 20 - Palmeiras

An intriguing player with a well-rounded skillset, Menino has already transitioned from centre-back to defensive midfield to right-back despite his young age. It is in the latter position where he impressed enough to earn a first Brazil call-up last year and only two players have provided more than his five assists in the 2020 Brazilian Serie A.

Moises Caicedo, 19 - Independiente del Valle

The past month or so has seen Caicedo brought to the attention of a wider audience – or, more specifically, Manchester United fans. The all-action midfielder was the teenager with the most goals (four), shots attempted (24), chances created (19), successful passes (748) and dribbles completed (23) in Ecuador's top flight in 2020, while his passing accuracy of 90.1 per cent was the highest among players to attempt 500 or more.

Billy Gilmour, 19 - Chelsea

Scottish talent Gilmour had shown real promise during his 11 Chelsea appearances last season before a knee injury in July laid him low. He returned to action last month with a few cameos off the bench, and there will be plenty hoping he can return to his previous level quickly. A loan move might be on the cards, but Frank Lampard has high hopes for the crafty midfielder.

Yunus Musah, 18 - Valencia

Valencia are going through another difficult spell, with off-field matters often overshadowing on-pitch performances. Nevertheless, in United States international Musah, they appear to have a reason for optimism. Another tricky winger, Musah's 38 dribbles is the second most among Los Che players this term and he became their youngest LaLiga goalscorer (17 years, 338 days) this century when netting back in November. He's one that got away from Arsenal.

Ander Barrenetxea, 18 - Real Sociedad

A nimble right-footed left-winger, Barrenetxea broke into La Real's senior side last season with 17 appearances in LaLiga. His eight starts this term is already an increase of five on the entirety of 2019-20 and he has been using that extra time on the pitch to excite. He has attempted 41 dribbles in LaLiga, and his 56 per cent completion rate is bettered by only seven players – all of whom are much older – among those to have tried at least 40.

Bryan Gil, 19 - Eibar (on loan from Sevilla)

If Barrenetxea embodies the modern 'inverted winger' style, then Bryan is very much a wide midfielder of the classic variety. A direct touchline-hugger, the left-winger's aim is almost always to beat his man and get a cross into the box, and he is catching the eye on loan at Eibar this term. Only five wingers in LaLiga can better Bryan's 49 open-play deliveries, though his 22.5 per cent accuracy is better than all but one of those with more cross attempts. He's also tried 44 dribbles, his 52.3 per cent completion putting him close to Barrenetxea.

Jaminton Campaz, 20 - Deportes Tolima

Campaz may not be a household name yet, but a move to Europe or one of South America's leading leagues is surely not far away. The attacker, who can play wide or through the middle, is an explosive player but also productive. No younger player had more goal involvements (five goals and four assists) and chances created (32) in Colombia's top division than Campaz.

Amad Diallo, 18 - Manchester United

Although United splashed a reported £19million on Diallo, the young Ivorian remains something of an unknown quantity. A left-footed right-winger, he has only been given a handful of opportunities in Atalanta's senior side – though he has often caught the eye with his ability on the ball. Given United's lack of options on the right flank, he might just establish himself sooner than some expect – either way, he will be one to monitor.

Pedri, 18 - Barcelona

As each week passes, more and more Pedri looks to be settling into the role as Lionel Messi's heir at Barcelona, but whether he's ready to take up such a mantle as early as this year is another matter. Messi's contract ends in June and so he could well depart – taking on his creative burden would be an unenviable task for a teenager, though Pedri is proving effective. He is creating a chance every 45 minutes on average in the league this term, the third most frequent in the squad among those to have played at least five times.

Talles Magno, 18 - Vasco da Gama

Are you really a Brazilian 'wonderkid' if you've not been linked with every major European club? Talles Magno fits the bill there and it's easy to see why there's interest. His end product still needs work, but his ability to excite is considerable – the 18-year-old has completed more than twice as many dribbles (106) as any other teenager in Brazil's Serie A between 2019 and 2020.

Karim Adeyemi, 18 - Salzburg

There has been a buzz around Adeyemi for a few years now as has previously impressed scouts with Germany's youth sides and during a fruitful loan spell at Liefering. Now back at Salzburg, he looks destined to be another serious talent off the club's impressive conveyor belt. Adeyemi is the only player to have been involved in four goals in a single Austrian Bundesliga this term, scoring and getting a hat-trick of assists in the 8-2 victory over St. Polten, while he set up a goal on his league debut for the club in June. A thrilling talent with great vision and dribbling abilities, Adeyemi may get even greater responsibility in 2021 following the departure of Dominik Szoboszlai.

Marcos Leonardo, 17 - Santos

It's still early days for Marcos Leonardo, though Santos clearly rate him highly – the striker's release clause is €100m. He's already the underage player with the most minutes played (296) and goals (one) in Brazil's top division this season, while he became the sixth youngest player to net in the Copa Libertadores (17y, 173d) when scoring a winner against Defensa y Justicia.

Youssoufa Moukoko, 16 - Borussia Dortmund

There's not much that hasn't already been said about Moukoko. He became the Bundesliga's youngest ever player in November when making his debut a day after his 16th birthday, before then also setting a new record for the league's youngest goalscorer in December. New coach Edin Terzic has already given him two starts – his next target will be to break records on the international stage with Germany. He couldn't get into their Euros squad, could he?

Matias Arezo, 18 - River Plate (URU)

Stocky, technically gifted and already proving decisive in front of goal with seven goal involvements (five goals, two assists) in 15 league matches, Arezo has a lot going in his favour. Whether he has the mentality or focus to not let the 'new Luis Suarez' labels distract him remains to be seen, but he's already the youngest Uruguayan (17y, 349d) to ever score a brace in the Copa Sudamericana having done so against Atletico Nacional in November.