Arsenal defender William Gallas is in doubt of missing the remainder of the season after suffering a knee injury in the Champions League clash with Villarreal.

The Frenchman had his leg trapped under him after a challenge from Villarreal's Giuseppe Rossi and the club fears there may be serious ligament damage.

Gallas has a medial ligament injury," Gunners boss Arsene Wenger told Canal Plus.

"The initial diagnosis doesn't appear to be very positive, but it will be clearer on Wednesday."