The 20-year-old has been ruled out for between six and eight weeks, although further tests will be carried out on Monday to investigate the full extent of the damage and decide what treatment will be given.
Fullback Rafinha also picked up an injury during the game and has torn ankle ligaments.
He will not need an operation, but will nevertheless miss the next four to five weeks, making him a doubt for the start of the season on 25
Both have been left out of the Bayern squad for its trip to
Hoffenheim claimed a vital 3-1 win against second-tier Kaiserslautern in the first leg of the Bundesliga play-off.