Schalke coach Jens Keller does not expect Lewis Holtby to return this winter because they are unable to afford him.
The midfielder left the Gelsenkirchen club for Tottenham in January of last year but has failed to become a first-choice regular at White Hart Lane.
Schalke have indicated they would be happy for him to return to the Bundesliga but not until Jermaine Jones leaves the club.
Keller said: "We can't really imagine such a transfer financially. Talks have not yet reached an advanced stage.
"Lewis has already played as a defensive midfielder under me. He can play there and is tactically very well-schooled."
Schalke will face Real Madrid in the last 16 of the UEFA Champions League next month.