Chief executive Hans-Joachim Watzke has admitted that Borussia Dortmund would be "open" to the prospect of re-signing Mario Gotze.
The 23-year-old, who joined Bayern Munich from Dortmund in 2013, was recently heavily linked with a summer switch to Liverpool.
However, should the playmaker leave the Allianz Arena, the Merseysiders may now face competition from his former employers.
"Mario is Bayern's player. His contract runs until 2017 and I have not heard, neither from the club or him, that they wish to end their collaboration," Bild quotes Watzke as saying.
"Under the current conditions, this is not a topic for us. But for every player who has merits for this club the door remains open, no question about it."
A section of Dortmund fans made their feelings about a potential Gotze return known yesterday when they unveiled a banner which read: "Milan or Madrid - the main thing is not Dortmund. Piss off Gotze."