Arsenal manager Arsene Wenger has confirmed that Francis Coquelin will spend the next three months on the sidelines with a knee ligament injury.
The 24-year-old was forced off the pitch in the first half of the club's 2-1 defeat at West Bromwich Albion on Saturday afternoon.
There were initial worries that the Frenchman would be ruled out of action for a long period, and Wenger has now revealed that test results have shown ligament damage, although the midfielder will not need surgery for the problem.
"It is what we feared, basically," Wenger told reporters. "Let's be realistic and count 12 weeks."
Coquelin has become a key player for Arsenal since returning from a loan spell at Charlton Athletic last season.