Dayot Upamecano has claimed he turned down an opportunity to join Manchester United as a teenager because Ralf Rangnick presented such a persuasive alternative.

The defender, who will leave RB Leipzig to join Bayern Munich at the end of this season, was targeted by United as a teenage prospect when he was with French club Valenciennes.

He elected to turn down United and move to Austrian club Salzburg, Upamecano says, after being wowed by Rangnick's precise vision for his career.

At the time, Rangnick was sporting director for Salzburg and Leipzig, with both clubs part of the Red Bull empire, and talking Upamecano into a move proved one of many successes he achieved in that role.

United had tempted the youngster, however, and Upamecano told The Athletic: "I was a young boy. I wanted to sign for them straight away. Manchester United! But then my parents took me aside and said: 'Let's think carefully about this'.

"We thought about it for a long time and then decided that going 'etape par etape' [step by step] was the best option for me. Everything Ralf said came true."

Upamecano was loaned out to Liefering before returning to make an impact with Salzburg while still in his teens, and at the age of 18, in January 2017, he was moved through the ranks to join Leipzig.

Rangnick, who had already enjoyed one spell as head coach of Leipzig, returned for another in 2018, and Upamecano said: "Ralf was the most important coach for me. He's a professor, a scientist of football, and he also cares about everything. He's always there for you with advice on matters football and non-football, every single day."

Before joining Bayern, Upamecano has the chance on Thursday to land a DFB-Pokal title with Leipzig as they head into the final in Berlin against Borussia Dortmund.

Julian Nagelsmann, who succeeded Rangnick in 2019, has been another major influence on the career of Upamecano, who describes the 33-year-old as "an unbelievable manager".

Like Upamecano, Nagelsmann will also move to Bayern at the season's end.

"He really takes you to another level," Upamecano said. "For example, because of Julian, I have improved a lot in terms of opening the game from the defence with precise passes into the midfield, and he told me to use my dribbling abilities in order to create spaces going forward."

That is borne out by data that shows Upamecano has progressed significantly while at Leipzig.

Following his mid-season arrival in 2017, Upamecano had an overall passing accuracy of 78.6 per cent in the Bundesliga, while his accuracy with passes ending in the final third of the field was just 46.2 per cent.

These numbers belong firmly in Upamecano's past, because his precision now shows a marked improvement.

In 2017-18, he stepped up those percentages to 83.7 and 55 in the Bundesliga, while attempting 130 passes into the final third of the pitch.

But in 2019-20, his overall accuracy stood at 89.1 per cent and his accuracy into the final third was a healthy 74 per cent, with Upamecano attempting 232 balls into that attacking area in league games. Each figure put him in the top 10 for Bundesliga defenders who played at least 20 games.

This season has seen a minor step back, but an 88.5 per cent total accuracy and 70 per cent accuracy into the final third continues to reflect well on the French defender, a player United must sorely regret failing to recruit.

Julian Nagelsmann has given his approval to RB Leipzig's choice of Jesse Marsch as his successor and future Bundesliga rival.

American coach Marsch will arrive from Salzburg, close affiliates of the German side, at the end of the season to take over from Bayern Munich-bound Nagelsmann.

The 47-year-old has spent two years as Salzburg boss and previously worked as an assistant coach with Leipzig so knows the club well.

Marsch was also head coach of New York Red Bulls from 2015 to 2018, and Nagelsmann sees him as an easy fit at Leipzig.

"I'm very happy that RB Leipzig have been able to quickly find a successor in Jesse Marsch," Nagelsmann said. "It was important to me that the club find a good coach and that they wouldn't have to deal with too much uncertainty following the news of my departure.

"Jesse Marsch is a very emotional coach and has a good connection to his players. I will definitely look to speak with him at the end of the season. I wish him all the best here and that he continues the club's success."

Nagelsmann will perhaps be mindful of being too helpful as the coaches cross and he leaves for Bayern as Marsch arrives at Leipzig, given they have been Germany's top two sides this season.

Bayern look like scooping the Bundesliga title for a ninth consecutive year. With 71 points from 31 games, they head Leipzig by seven points with three rounds of games remaining.

However, Leipzig are very much in the hunt for cup glory as they head into Friday's DFB-Pokal semi-final against Werder Bremen.

The winner of that tie will face either Borussia Dortmund or Holstein Kiel, the second-tier team that knocked out Bayern in the early stages of the tournament.

"Of course, it would be nice to end my time here by winning the DFB-Pokal," Nagelsmann said on Thursday.

"The pressure is there, but that's normal. If you've reached the semi-finals with your team, then it's obvious that you want to advance to the final and win there."

Quoted on Leipzig's official website, Nagelsmann said: "There's nothing worse than losing a final. If we have the chance to win the trophy, then we'll do everything possible to make that happen.

"We don't need any extra motivation for Friday night. The cup is motivation enough. The team will give it everything they have to meet the expectations. They are highly motivated.

"I still have a good relationship with the team and spoke to the lads. All the outside noise won't affect them. All of my players want to continue improving.

"Our goal is to make it to [the final in] Berlin. We also want to break the 67-point mark in the Bundesliga, in order to set a new [club] record this season."

Jesse Marsch will take over as head coach of RB Leipzig when Julian Nagelsmann heads to Bayern Munich at the end of the season.

The switch sees Marsch leave Salzburg, affiliates of Leipzig, to rejoin the club he previously served as an assistant coach.

Leipzig said Marsch had agreed a two-year contract and would assume his new role on July 1.

Marsch has been a head coach before, most notably leading New York Red Bulls from 2015 to 2018, and the American should prove an easy fit with the German Bundesliga side.

Leipzig CEO Oliver Mintzlaff said: "In Jesse Marsch, we have been able to recruit our main head coach and quickly fill the most important position in the sporting side of the club with a top coach.

"Jesse has been part of the Red Bull football group for over six years now and has done incredible work in all his roles so far, constantly developing step by step.

"It's of course a great advantage that he already worked for a year at RB Leipzig. Jesse knows the club, the city of Leipzig and, above all, the club and playing philosophy.

"Alongside his qualities as a coach, Jesse is characterised above all by his positively ambitious style, which he uses to motivate and engage the people and around the club.

"We're looking forward to working with Jesse Marsch and to continuing our successful path with him."

It's November 25, 2020. A young German winger stands on the touchline anxiously waiting to step on to the Allianz Arena pitch for his Champions League debut in his hometown.

But as he waits to be allowed on, there are people watching both on television and in the largely empty stands who know this isn't how it should've been.

Rather than wearing the all-red of Bayern Munich, Karim Adeyemi jogs on in the all-black of Salzburg with the Austrian champions 3-0 down.

A technically gifted and supremely fast winger, Adeyemi has long been considered one of Germany's most promising young players, having cost Salzburg a reported €3million when he was 16.

Adeyemi had left Bayern six years earlier and is a situation that has dominated much of his early professional career, with questions about why he left never far away.

Now 19, Adeyemi has previously spoken at length about his attitude as a kid, how learning wasn't much to his liking and distraction was a regular nuisance to him.

These factors certainly didn't help at Bayern. Neither, Adeyemi alleged in the past, did the club showing little support to players who strayed from "the plan". The collective, rather than individualistic talents, was prioritised.

But to speak to him in 2021, Adeyemi comes across as grounded and professional, yet driven, well aware of the level he wants to reach.

"I think it's a dream for every player to play in the Bundesliga or Premier League one day," he tells Stats Perform News. Yet, should he end up in England, it's fair to say he'll have taken the long route.

Chelsea were a keen admirer of Adeyemi before he joined Salzburg, the youngster confirming in the past that he turned down a move to Stamford Bridge in favour of Austria.

"I decided that with my family because I thought that Salzburg was the best destination for me," he continued. "Their playing style fits me well and we harmonised perfectly. I got along well with Christoph Freund [Salzburg sporting director] and everyone else. That's why I decided to join this club."

But while the average football fan might question his choice, Adeyemi's former coach at Unterhaching – with whom he spent the six years between Bayern and Salzburg – believes it was a mature decision that made perfect sense.

"Surprised? No, not at all. For him, Salzburg was the right club," Marc Unterberger told Stats Perform News. "Their philosophy suits him perfectly, and the proximity to Unterhaching, where his family still lives, is ideal.

"What is being done there, especially in training young players, is absolutely remarkable."

But what exactly has that meant for Adeyemi? The teenager adds: "It was my plan to first join Liefering [on loan] when I arrived at Salzburg. I wanted to perform well there and show my skills, then I wanted to have more and more contact with the first team [at Salzburg], and I think for every young player it's first of all important to get settled. Now I am at the first team and I am happy about it. That was my plan so far."

After spending a year and a half at Liefering, who essentially act as a B team for Salzburg, Adeyemi returned to his parent club having caught the eye in Austria's second tier.

He scored 15 goals and got eight assists in 35 league games for Liefering, strong evidence that he was ready for the step up.

Adeyemi hasn't been quite so explosive with Salzburg, only having a hand in goals in six of his 29 Austrian Bundesliga matches, but the key factor here is that he is having to remain patient – only nine of those 29 games were as a starter.

"Well, you can never be completely satisfied," he explained. "You always have things to improve. It was the same for me when I played in Liefering. I always want more. It's exactly the same here in the first team. I always say I am never satisfied with what I do, I always want more, and I think that's what I am focusing on.

"I am trying to improve my game together with the coaching staff. I'm trying to have progress in my development. Nobody knows what happens in the future."

It is a display of maturity and realism that belies many of the stories that have followed Adeyemi during his fledgling career. Unterberger believes the youngster is often shown in a negative light, adamant most kids are prone to distraction.

"I find that he is portrayed too negatively. Of course, Karim wasn't a classic academy player. He had his own thoughts on how to deal with things. We never wanted to change him completely, and I think we succeeded quite well. Karim is a really great guy and a great person.

"Until the time Karim came to us, we had never had such an exceptional player in our youth division. Of course, as a young person, you benefit from being accepted for who you are, but I would like to make it very clear that there was no situation within the team in which Karim behaved in such a way that we as a club were forced to act. On the contrary, over time he developed more and more towards putting himself at the service of the team.

"He was easily distracted, that's right, but let's be honest, something like this is normal when young people develop."

After all, Unterberger arguably knows Adeyemi better than any other coach.

"I can still remember it very well, the first time I saw him play in an Under-11 tournament," he recalls. "Back then he was still playing for TSV Forstenried. My first thought was: 'We absolutely need this player'. Fortunately, it worked out later!"

That might be something of an understatement in reality. The €3m fee that Unterhaching received made him the most expensive German under-18 player ever, while 2019 saw him win the Fritz-Walter Gold Medal, an award handed out to Germany's best youth player. Previous winners include Timo Werner, Emre Can and Mario Gotze.

And he has certainly shown flashes of his significant potential. In November, he became the first player this season to have a hand in four goals (one scored, three set up) in a single game in the Austrian Bundesliga. Only one other has matched that feat this term: his team-mate, Mergim Berisha. In December, he broke Salzburg's record for their youngest ever scorer in the Champions League.

Yet Adeyemi recognises he still has a long way to go.

"I can only talk for myself and not for the other players. I think if you feel comfortable within a team and you get your chances, then there's a possibility [of finding the right fit]. That's how it is between Salzburg and myself. I will continue to work hard for that. I want to develop more and become a man."

Given the talents Salzburg and their Red Bull sister club RB Leipzig have produced in recent years, few would doubt Adeyemi's in the right place to spread his wings.

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.