Bayer Leverkusen chief executive Wolfgang Holzhauser has warned Chelsea off striker Andre Schurrle.
Blues owner Roman Abramovich is expected to make a new bid for the Germany international.
But Holzhauser told the Daily Mail: "We will not sell him this season, no matter how much they (Chelsea) want him and no matter how much they offer. Next year may be different, but he will not leave this season."