Bayern Munich have confirmed that Holger Badstuber has torn cruciate knee ligaments and will miss the next six months of the season.
The 23-year-old defender lasted only 35 minutes of Saturday's draw with Borussia Dortmund in the Bundesliga before being taken off the field in agony.
A scan carried out by Bayern's club doctor Hans-Wilhelm Muller-Wohlfahrt this morning confirmed the worst fears and the player will now undergo surgery on Monday before beginning his recovery, which should take approximately six months.
"It is very bitter," said Bayern coach Jupp Heynckes after Saturday's 1-1 draw in Munich.
"The players were very shocked. He was only just getting back into a rhythm.
"This is very bitter for the lad."
It was clear from the moment the Germany defender went down that the injury was serious.
"He said that he just got stuck in the grass," said Bayern's chairman Karl-Heinz Rummenigge on his club's website. "It just went snap immediately."
Badstuber has figured in 12 matches for Bayern this season and has already been sidelined with torn muscle fibres, an injury he had only just put behind him.
He is therefore ruled out of Bayern's final Champions League group game against BATE Borisov on Wednesday and will only be able to feature in the competition again this season if Bayern reach the final, and his recovery goes according to plan.