Chelsea are reportedly targeting a move for Christopher Nkunku as Thomas Tuchel eyes a reunion with the former Paris Saint-Germain youngster.
The Frenchman has been in fine form for Red Bull Leipzig this season, including a notable hattrick against Manchester City in the Champions League.
Those types of performances have attracted the attention of the Blues, Manchester City and Real Madrid, according to Foot Mercato.
Nkunku's value has soared since he left PSG for Leipzig in the summer of 2019 as the German side paid £13million for the winger.
And Arsenal will be kicking themselves as they were one of the teams interested in him at the time.

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Former boss Unai Emery looked into the possibility of a loan move in January 2019 but signed Denis Suarez instead - as PSG wanted a permanent deal for Nkunku.
Nkunku would then make the switch to Germany six months later.
Chelsea will be hoping to capitalise on their mistake and Tuchel knows Nkunku better than most.
The Stamford Bridge boss gave him as much playing time as he could in Paris, but it was difficult to make him a regular starter, given PSG's star-studded line-up.
And it wasn't enough to stop him from signing a five-year deal with Leipzig which runs out in 2024.
Nkunku spent five years with the PSG academy system and made 78 appearances for the first team, scoring 11 goals in the process as he picked up three Ligue 1 titles, two Coupe de France trophies and a pair of Coupe de la Ligue wins.
But he never really was able to make himself a first pick in Paris.
However, new RBL boss Jesse Marsch insists Nkunku is the complete package - albeit one that has plenty of room for improvement.

He said: "Christopher has no weakness. He is young and still wants a lot more. Working with him is very pleasant, because he is really intelligent and has a lot of potential."
Leipzig sporting director Markus Krosche hailed the 23-year-old after he made the move to Germany.
He told the club’s official website: “Christopher Nkunku’s skill set fits very well with our profile.
“He is a dynamic and versatile attacking player and thus increases the variability in our game.
“We are delighted that this highly talented player has chosen our club and we believe he will help us with his qualities.”