Bayern face an attacking crisis after Miroslav Klose was ruled out of the Bundesliga clash with Hanover on Saturday.
A scan confirmed the 29-year-old, the top scorer at last year's FIFA World Cup, has strained knee ligaments, the club said on Tuesday.
Klose, who has withdrawn from the German squad for Wednesday's friendly with England, has been ordered not to run or train with the Bayern squad for the next 10 days and will be examined again next Wednesday.
Klose was injured in the early stages of last Saturday's 4-0 rout of Werder Bremen after he was felled by a heavy tackle from Bremen's Brazilian defender Naldo.
Klose's misfortune means Bayern have just one fit striker, Italian FIFA World Cup winner Luca Toni.
German international Jan Schlaudraff is still several weeks away from a return to training after back surgery, while Lukas Podolski made his first competitive appearance for four months with the reserves last weekend.
"Obviously I lack stamina, freshness and match practice, but I'll remedy that over the next few weeks," the 22-year-old German international striker told the Bayern website.
Coach Ottmar Hitzfeld will monitor Podolski, voted the best young player at last year's FIFA World Cup, and may give him a place on the bench against Hanover.
Bayern's midfielder Jose Ernesto Sosa will also miss the league leaders' home game against Hanover after the Argentinian suffered an attack of lumbago, and has been told to rest for the next ten days.