Arsenal defender Per Mertesacker has undergone ankle surgery and could be out for the 'long term'.
The German centre-half sustained the injury in last weekend's 2-1 win over Sunderland when he slipped awkwardly allowing the Black Cats to score the opening goal.
It was initially thought that Mertesacker would only miss one or two matches but the injury was much worse than originally anticipated and he will now be on the sidelines for a while according to manager Arsene Wenger.
"How long I don't know. He had reconstruction of his ligaments, so it will be long term.""Unfortunately he has had surgery and we have lost him for a while," the Gunners boss told his club's official website.
