The 23-year-old is believed to have suffered the problem in training on Thursday.
"Cruciate ligament rupture, six months out," the Moroccan tweeted.
Ligue 1 champions Montpellier are currently 15th in the table following four defeats from their opening eight matches.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Paris Saint-GermainPSG | 11 | 9 | 2 | 0 | 33 | 10 | 23 | 29 |
| 2 | MonacoMonaco | 11 | 7 | 2 | 2 | 18 | 8 | 10 | 23 |
| 3 | Marseille | 11 | 6 | 2 | 3 | 24 | 15 | 9 | 20 |
| 4 | Lille | 11 | 5 | 4 | 2 | 18 | 11 | 7 | 19 |
| 5 | Lyon | 11 | 5 | 3 | 3 | 18 | 15 | 3 | 18 |
| 6 | Nice | 11 | 4 | 5 | 2 | 21 | 11 | 10 | 17 |
| 7 | Reims | 11 | 5 | 2 | 4 | 19 | 15 | 4 | 17 |
| 8 | Lens | 11 | 4 | 5 | 2 | 12 | 9 | 3 | 17 |
| 9 | Auxerre | 11 | 5 | 1 | 5 | 20 | 19 | 1 | 16 |
| 10 | Toulouse | 11 | 4 | 3 | 4 | 13 | 11 | 2 | 15 |
| 11 | StrasbourgStrasbourg | 11 | 3 | 4 | 4 | 20 | 22 | -2 | 13 |
| 12 | Brest | 11 | 4 | 1 | 6 | 14 | 19 | -5 | 13 |
| 13 | Rennes | 11 | 3 | 2 | 6 | 13 | 18 | -5 | 11 |
| 14 | NantesNantes | 11 | 2 | 4 | 5 | 14 | 17 | -3 | 10 |
| 15 | Angers | 11 | 2 | 4 | 5 | 13 | 20 | -7 | 10 |
| 16 | Saint-EtienneSt Etienne | 11 | 3 | 1 | 7 | 10 | 25 | -15 | 10 |
| 17 | Le HavreLe Havre | 11 | 3 | 0 | 8 | 8 | 23 | -15 | 9 |
| 18 | Montpellier HSCMontpellier | 11 | 2 | 1 | 8 | 11 | 31 | -20 | 7 |
| > Ligue 1 Full Table | |||||||||
