Mainz's general manager Christian Heidel believes selling Jan Kirchhoff to Bayern Munich this month is highly unlikely.
There has been speculation the Bavarians may try to sign the player straight away.
Kirchhoff has signed a contract with Bayern from July, when his current deal with Mainz expires, but given the injury to Holger Badstuber and doubts over Daniel van Buyten's fitness, it has been suggested that Bayern may try to sign the 22-year-old six months early.
"The probability of Kirchhoff leaving us now is practically zero," he told the Mainz Allgemeine Zeitung newspaper.
"I am not saying that just to push his value up, but because if we were to sell him then we would have to buy two new players immediately, one central defender and one defensive midfielder.
"Any money we earned from selling Jan would just be reinvested in them."
Bayern are not going to give up on the transfer, though, with their director of sport Matthias Sammer saying: "The ball is in Mainz's court.
"I have read that the Mainz coach does not want the player to go, but the manager may do under certain circumstances.
"Until we get a signal we are relaxed about it. We have him under contract from the summer anyway."