Bayer Leverkusen and Germany striker Stefan Kiessling is facing a long period on the sidelines after tearing a ligament in his left leg.
The 26-year-old suffered the injury early in Sunday's 0-0 draw with former club Nurnberg and he was stretchered off in the 12th minute.
Kiessling has now had his leg put in plaster and will be facing several weeks of rehabilitation, meaning he will miss Germany's Euro 2012 qualifiers against Turkey and Kazakhstan in October.
Leverkusen coach Jupp Heynckes said in a statement: "Bad luck with injuries has hit us hard early in the season. We must now find ways to deal with it."
Summer signing Michael Ballack suffered a fractured shin earlier in September and was ruled out for six weeks.
But Leverkusen have had better news regarding striker Patrick Helmes, who is only expected to miss one match after limping off with a thigh problem against Nurnberg.
Club executive Wolfgang Holzhauser told Kicker: "Helmes is also injured, however, he might be back sooner rather than later."