Arsenal boss Arsene Wenger has admitted that Mikel Arteta could be out for a "while" after picking up a calf injury in his side's win over Borussia Dortmund.
The Spaniard sustained the injury in the second half of the Champions League clash, and Wenger has revealed that the outlook is bleak for a quick return, while Yaya Sanogo also limped out of the match.
He told Sky Sports News: "Mikel Arteta doesn't look good - it's a calf. I think he will be out for a while.
"The injuries are difficult to take on the chin. We go into many games and we need as many available."
The Gunners qualified for the knockout stages of the Champions League with their victory at the Emirates Stadium.
