Arsenal manager Arsene Wenger has confirmed that Aaron Ramsey is back in the squad ahead of Tuesday's Champions League match against Dinamo Zagreb, but Francis Coquelin is facing "months" on the sidelines.
Ramsey has been out of action since October after he suffered a hamstring injury in the Gunners' 2-0 win over Bayern Munich.
The club have received a boost as the Welshman has returned to training, but Coquelin is feared to have damaged his knee ligaments in last weekend's 2-1 loss to West Bromwich Albion.
The Gunners are yet to learn the extent of the injury, but Wenger expects the midfielder to be sidelined for "at least a month".
"Coquelin and Arteta are out," Wenger told the club's official website. "Arteta is short term and Coquelin is longer. How big the damage is we don't know but we will know for certain this [Monday] afternoon. Everyone from Saturday's game is available and Ramsey is available.
"[Coquelin is out for] at least a month. I'm a bit cautious as we have had so many bad surprises on the scans, but the team for the next few months will be without Coquelin."
Arsenal need to beat Zagreb to have a hope of reaching the knockout rounds of the competition.
