The 30-year old Frenchman had been making huge strides in his bid to bounce back from a nine month lay off when he appeared in the reserves final game of the season against Liverpool last month but he is now back on crutches as part of his joint has failed to heal fully.
Manager Sam Allardyce remained unconcerned and expected the former Olympique Lyon player to be ready for pre-season training in a couple of months time.
"He will be back for pre-season training" said Allardyce today.