Montpellier midfielder Karim Ait-Fana is out for six months after injuring his right knee during a training session last week.
Ait-Fana, 23, underwent tests after suffering the injury on Thursday and wrote on Twitter: ''The verdict after the medical tests is that I have ruptured my anterior cruciate ligament, and I will be out for six months."
It is another setback for the Morocco international, who was ruled out for five months by an ankle injury last year and played only 11 games as Montpellier won last season's Ligue 1 title.
Ait-Fana's latest injury is a blow for René Girard's champions, who have started the season sluggishly and are 15th in the table. He has played in both his club's Champions League games, scoring in the 2-2 draw away to Germany's Schalke.