Bayer and Cameroon national team forward Christian Kofane, 20, has refused to extend his contract with the club.
According to Bild, his decision comes as English clubs Manchester United and Arsenal are showing interest in signing him.
Bayer, based in Leverkusen, competes in Germany’s Bundesliga. Contract negotiations and interest from other clubs can influence a player’s future, though no further details about Kofane’s plans have been reported.