The Gambia's Dawda Bah is set to be out for the next six months - after just one game for his German club Augsburg.
The 27-year-old picked up a knee injury in training on Wednesday and immediately underwent surgery.
"It is bitter news for Dawda, both he and us had imagined a different start to his time here," said Augsburg's managing director Andreas Rettig.
The midfielder signed from Finland champions HJK Helsinki in August and only made his debut last Friday.
Bah came on as a substitute in Augsburg's 4-1 Bundesliga loss to Leverkusen.
The Bundesliga newboys say The Gambia striker underwent surgery after "severe bone and soft tissue damage" to his left knee in training on Wednesday.
It is a further blow to Augsburg who were hoping that Bah would help provide cover for the injured Cameroonian midfielder Marcel Ndjeng in the coming weeks.