Bayern Munich winger Kingsley Coman is expected to miss the rest of the season after surgery on his ankle.
The 21-year-old was hurt in a collision with Mathew Leckie during the Bundesliga leaders' 0-0 draw with Hertha Berlin on Saturday.
Head coach Jupp Heynckes said afterwards Coman had avoided ligament damage and hoped the problem would not prove to be serious.
However, the club confirmed on Monday the France international has had to have an operation that could cause him to sit out the rest of 2017-18.
It also leaves his participation at the World Cup in Russia in serious doubt.
"French international Kingsley Coman suffered a rupture of the syndesmosis ligament above the left ankle during Saturday's 0-0 draw against Hertha Berlin," Bayern said in a brief statement.
"This resulted in a follow-up on the following day. Already this Monday, Coman was in Tubingen, where Dr Ulrich Stockle operated successfully.
"The 21-year-old will be out for several weeks."
Coman has made 32 appearances in all competitions this season, scoring seven goals.