Wolfsburg have told striker Nicklas Bendtner that he must improve his fitness if he wants to stay at the club.
The 27-year-old is currently training on his own after the Bundesliga side made it known that he was not up to the physical standard required.
Director of sport Klaus Allofs has now suggested that the Dane could be sold if he does not sharpen up before the start of the season.
"The demands on a footballer in Germany are different to in England or in Denmark," he told Sport Bild. "If anybody wants to play for us then they can follow us. Anybody who doesn't want to do that and does not get in line has no place at this club."
Bendtner scored five goals in 28 appearances for Wolfsburg last season.
