Boka suffered the ligament damage during the 3-3 draw with Hoffenheim at the weekend.
The left-back was immediately taken to hospital, following an challenge from Sejad Salihovic during the game.
Boka suffered the ligament damage during the 3-3 draw with Hoffenheim at the weekend.
The left-back was immediately taken to hospital, following an challenge from Sejad Salihovic during the game.
