Eintracht Frankfurt midfielder Pirmin Schwegler is facing three months on the sidelines after undergoing knee surgery.
The Switzerland international is a key figure in the Eintracht side and is under contract for a further two years.
However, he is now facing a battle to return to action before the Bundesliga's winter break after the 26-year-old hurt his left knee.
"We are delighted to know it has been a successful surgery," Eintracht general manager Bruno Hubner told Deutsche Presseagentur.
"We are looking for a swift recovery for Pirmin Schwegler from his injury, but we are aware that it will take time."
Meanwhile, Eintracht executive Heribert Bruchhagen has denied rumours that attacking midfielder Alexander Meier, who is out of contract at the end of the season, will be allowed to leave the club on a free transfer in January.
Bruchhagen said: "The news of Alexander Meier being able to move clubs on a free transfer come January 2014, as has been reported in the media, is asserted without any substance.
"These reports are totally wrong. Alexander Meier is under contract with our club until June 2014."