Bayern Munich manager Jupp Heynckes fears that midfielder Toni Kroos could be out of action for a "long time" after picking up an injury against Juventus on Tuesday.
The 23-year-old was forced off during the 16th minute of the Germans' 2-0 win over the Italians in the first leg of their Champions League quarter-final clash.
Heynckes admits that he is worried about the prospect of losing one of his most influential players at a crucial stage of the season.
"An initial diagnosis by FCB chief medical officer Dr Hans-Wilhelm Muller-Wohlfahrt suggests the Germany international has ruptured a group of adductor muscles in his right hip and now faces several weeks on the sidelines," a statement on Bayern's official said.
"This is obviously very bitter," Heynckes added.
"It's just such a shame for a young player who has played great this season."
The return leg takes place next Wednesday.