Dayot Upamecano has long been linked with Manchester United and Manchester City - why are both clubs so keen on a summer move?
Upamecano's name first became linked with the north west as far back as 2015, when still a youngster with French side Valenciennes. The-then 16-year-old had not even made his debut for the Ligue 2 side at the time, but had a sufficient buzz around his name to suggest he was destined for bigger things.
That didn't take long. He joined Red Bull Salzburg that summer for around €2.2m (£2m), went on to make his first-team debut that season and two years later, moved within the group's ownership to join RB Leipzig in 2017.
There, he continued to impress and was shortlisted for the European Golden Boy award - showcasing the continent's brightest young talent - a year later.
Now, he's back on the radar for both United and City, who are both planning to add to their defensive ranks when the transfer window opens.
What's Upamecano's story?
Since joining Leipzig in 2017 Upamecano has found himself a mainstay at centre-back, with the young club finishing second, third and sixth in the three seasons he has been with the club.
In his first full season after his January move, he would start 25 of 34 Bundesliga games for Leipzig, which led to a place in the 40-man shortlist for the 2018 Golden Boy award, voted for by sports journalists across Europe.
Upamecano hardly needed that acclaim to make himself known. By then he was already said to be touted by some of Europe's biggest clubs. His agent later came out and said Manchester United could have bought him for as little as £5m before his move to Salzburg, but added the move fell through due to "broken promises".
In an interview with French publication So Foot in February 2019, Thierry Martinez claimed United reneged on key aspects of their initial proposal, withdrawing their offer to buy his client a flat and capping the number of return flights for the youngster's visiting parents to just six, terms which saw any potential deal collapse.
Moving forward to this season, he has started six of Leipzig's eight Champions League games en route to a first-ever quarter-final spot - and played the full 90 in their comfortable 3-0 last-16 second-leg win over Tottenham in March.
How's he impressed?
In a Bundesliga season where Leipzig have contributed the joint-tightest defence in the division, Upamecano has been a rock at the back.
A ball-playing centre-half with a pass completion of almost 90 per cent, the Frenchman has also completed more tackles than any of Leipzig's defenders, made almost two interceptions per game and the most clearances of his team-mates.
"He loves defending, getting the ball off opponents," Jean-Claude Giuntini, France U17 coach and Upamecano's former international manager has said of his ex-player.
His pace is an impressive tool in his armoury too. Although adept enough not to need bailing out by it, he has been given high praise by no less than team-mate Timo Werner - a man who knows a thing or two about a sprint - having come up against the defender regularly in training.
"I've not seen a faster centre-back, and Dayot has an unbelievable physique," he has said. "He can become as good as Jerome Boateng if he can keep improving."
At barely 21 years old, and not 22 until October, there's clearly a lot more to come from Upamecano. He was strongly linked with a move to Arsenal last summer before they plumped for William Saliba instead, but with both Manchester clubs now knocking on the door, a move to the Premier League could finally materialise.
Sky in Germany report that Bayern Munich are also eyeing a move for the defender, having had to move David Alaba to centre-back to cover for the injured Niklas Sule this season, while the major clubs in Spain are also considering making a move.
Even in an era where clubs may prove tentative around high spending on the back of the financial impacts of coronavirus, a £52.5m release clause and the potential of Upamecano to keep developing for years to come presents an attractive prospect for any club that decide to take the plunge.