The former Manchester United forward suffered the injury during his side's 3-0 defeat at the hands of Real Madrid on Wednesday.
The full extent of the problem is not yet known, but the 24-year-old is likely to miss the majority of the season.
The Italian moved to the La Liga side in 2007.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Barcelona | 8 | 7 | 0 | 1 | 25 | 9 | 16 | 21 |
| 2 | Real Madrid | 9 | 6 | 3 | 0 | 19 | 6 | 13 | 21 |
| 3 | Villarreal | 9 | 5 | 2 | 2 | 17 | 17 | 0 | 17 |
| 4 | Atletico MadridAtletico | 8 | 4 | 4 | 0 | 12 | 4 | 8 | 16 |
| 5 | Osasuna | 9 | 4 | 3 | 2 | 13 | 14 | -1 | 15 |
| 6 | Athletic Bilbao | 8 | 4 | 2 | 2 | 12 | 8 | 4 | 14 |
| 7 | Mallorca | 9 | 4 | 2 | 3 | 9 | 8 | 1 | 14 |
| 8 | Rayo Vallecano | 9 | 3 | 4 | 2 | 11 | 9 | 2 | 13 |
| 9 | Celta Vigo | 9 | 4 | 1 | 4 | 16 | 15 | 1 | 13 |
| 10 | Real BetisBetis | 8 | 3 | 3 | 2 | 8 | 7 | 1 | 12 |
| 11 | AlavesAlaves | 8 | 3 | 1 | 4 | 11 | 12 | -1 | 10 |
| 12 | Espanyol | 9 | 3 | 1 | 5 | 9 | 13 | -4 | 10 |
| 13 | GironaGirona | 8 | 2 | 3 | 3 | 9 | 11 | -2 | 9 |
| 14 | Sevilla | 8 | 2 | 3 | 3 | 8 | 10 | -2 | 9 |
| 15 | Real Sociedad | 8 | 2 | 2 | 4 | 6 | 7 | -1 | 8 |
| 16 | Getafe | 9 | 1 | 5 | 3 | 6 | 7 | -1 | 8 |
| 17 | Leganes | 9 | 1 | 5 | 3 | 5 | 9 | -4 | 8 |
| 18 | Valencia | 9 | 1 | 3 | 5 | 5 | 13 | -8 | 6 |
| 19 | Real ValladolidValladolid | 9 | 1 | 2 | 6 | 5 | 19 | -14 | 5 |
| 20 | Las PalmasLas Palmas | 9 | 0 | 3 | 6 | 9 | 17 | -8 | 3 |
| > La Liga Full Table | |||||||||
