Bayern Munich says defender David Alaba will be out for several weeks after hurting a knee in the 2-0 Champions League victory over Roma.

Alaba set up Bayern's first goal in Wednesday's match and has been one of the team's best players in recent weeks.

He joins a growing list of injured players. Backup striker Claudio Pizarro has been ruled out for weeks with a torn muscle in his right thigh.

Bastian Schweinsteiger, Holger Badstuber, Javi Martinez and Thiago Alcantara are also sidelined.