Manchester City are reportedly fearful that Leroy Sane is considering his future at the club.
The Germany international moved to the Etihad Stadium from Schalke 04 in the summer of 2016. In 129 appearances for the Premier League champions, Sane has contributed 38 goals and 45 assists.
The attacker will see his contract with the Citizens expire at the end of the 2020-21 campaign, though, and according to Metro, talks over a new deal have stalled.
The same report claims that Pep Guardiola's side fear that Sane is considering offers from elsewhere, with Bayern Munich believed to be considering a summer bid.
The 23-year-old has scored 15 times and contributed 18 assists in 43 appearances for City this term.