MUNICH, Germany (AFP) - Bayern Munich defender Marcell Jansen is an injury concern for the Bundesliga giants ahead of Monday night's German Cup first-round clash at third-division Wacker Burghausen, the club announced on Saturday.

The 21-year-old German international only returned to training on Friday after bruising his upper arm and then damaged a knee ligament on Saturday.

"It is questionable whether he will be fit for Monday," said Bayern coach Ottmar Hitzfeld, who will have seven injured players in his squad if Jansen fails to recover.

All in all, defenders Willy Sagnol, Valerien Ismael and teenager Mats Hummels, as well as strikers Jan Schlaudraff, Lukas Podolski and Luca Toni are all struggling.

If Marcell also joins the list, Christian Lell will step in for Monday night.

Italian World Cup winner Toni, still struggling with a knee injury, will miss the trip to minnows Burghausen, as well as next Tuesday's final pre-Bundesliga warm-up in Majorca.

As a result, teenage reserve striker Sandro Wagner will retain his temporary place in the first-team squad at least until after the cup tie.