Schalke are in talks with Chelsea over bringing defender Baba Rahman back to Gelsenkirchen on loan.
The Ghanaian full-back moved to the Bundesliga 12 months ago on what was supposed to be a season-long stint until a serious knee injury while playing at the Africa Cup of Nations in January brought an early end to his campaign.
His ongoing recovery will be a factor in any deal but Schalke remain keen on the 23-year-old, who made 20 appearances for the club in the first half of last campaign.
"We are in talks with the player, his advisor and Chelsea," said Schalke's sporting director Christian Heidel.
"Ultimately, it is about when Baba will be able to play again. No decision has yet been made."
Rahman moved to Stamford Bridge from Augsburg two years ago but made only 23 appearances during the 2015-16 season, with Cesar Azpilicueta preferred at left-back.
He has not played for Chelsea since May 2016 and it appears he is not part of Blues manager Antonio Conte's first-team plans.