Bayern Munich have been dealt a blow ahead of next week's Champions League semi-final first leg against Real Madrid with the news midfielder Arturo Vidal needs surgery.
The Chilean suffered a setback on Sunday in his first training session since he sustained a knee injury against Sevilla earlier this month.
Vidal has definitely been ruled out of the German Cup semi-final against Bayer Leverkusen on Tuesday and he looks unlikely to make next Wednesday's meeting with Madrid too.
"He slipped and went down," boss Jupp Heynckes said on Bayern's official website.
"I've just spoken to (team) doctor (Hans-Wilhelm) Muller-Wohlfahrt on the phone. He's had an MRI scan. Arturo has a loose body in his knee. That's preventing him stretching.
"He's already on his way to Augsburg. He needs keyhole surgery on his knee. Arturo will definitely be out of action for a while."
Prior to missing the second leg against Sevilla through injury, Vidal had appeared in all but one of Bayern's Champions League games this season.