Bayern Munich will be without Miroslav Klose for up to four weeks after scans on the striker's injured ankle revealed the need for surgery.
Klose limped out of the 3-0 win over Bochum on Saturday and an assessment has revealed the Germany international has suffered a partial tear to the tendon in his right ankle.
Klose will now miss Germany's forthcoming World Cup qualifiers against Liechtenstein and Wales and is an early doubt for next month's Champions League quarter-finals.
"This is obviously a bitter blow," admitted coach Jurgen Klinsmann.
"We can only hope that the operation goes well and Miro gets back on his feet quickly."
Bayern are already without fellow striker Luca Toni with an Achilles problem.