Bayern Munich has warned Chelsea that they will return for Callum Hudson-Odoi's £ 35 million in the summer – and the Blues are faced with fighting.
German champions Karl-Heinz Rummenigge said: "We want the best quality of players."
Chelsea rejected a number of applications for the 18-year-old Hudson-Odoi – target number 1 Bayern for the January transfer window – but the girl is still keen to give her up.
Chelsea was not sent by a transfer request before the last week's closing date, and after that, Maurizio Sarri claimed last week that Hudson-Odoi "should respect the club's academy".
Bayern director, Hasan Salihamidzic, hit the player last month with the international tide under 19 years of age desperate to leave after failing to start one Premier League game for Chelsea.
Bayern chairman Karl-Heinz Rummenigge said: "We want the best quality of players in Bayern and Hasan [Salihamidzic, director] completely convinced of this player. That's the reason.
"The only thing that Hasan would have been happy to finish was this Chelsea player, because he had dropped in practice in love with this player because of his quality.
"We will not deny now that the aggressive court did not go too well in London, but you can not forget that Hasan Salihamidzic must sign the player somewhere.
"He was not directly in touch with him personally, as that was not allowed all but the player still needed a sign of Bayern Munich behind him."
Chelsea is also faced with fighting to keep another of his stars, Reece James, with Brighton and Palace Palace among a number of interested Premier Clubs.
The back of the age of 19 does not have to play one game for the Blues. It's on long-term loan spelling with the Wigan Championship side. But he impressed him in the middle of the middle during the second 2-1 victory over QPR and has already been dumped for a great future.
Wigan's head, Paul Cook, said: "He's a player every month, and he's a man of the game almost every week."