Bayern Munich defender Holger Badstuber will miss the remainder of the Bundesliga season after suffering a torn cruciate ligament in the 1-1 draw with Borussia Dortmund on Saturday.
Badstuber, who only returned from a muscle injury 10 days ago, fell awkwardly in a challenge with Dortmund's Mario Gotze in the first half.
Bayern later confirmed the severity of the blow, indicating the Germany international will play no further part for club or country until May 2013.
"Holger Badstuber has sustained a cruciate ligaments tear and is expected to be out of action for half a year," the Munich club in a statement.
The timing could not have been worse for Badstuber, with Bayern leading the Bundesliga by eight points as they prepare to take on BATE Borisov in their last Champions League group stage match.