Walcott will miss Wednesday’s match at the Emirates Stadium with a shoulder injury suffered during Arsenal’s 5-2 North London derby win over Tottenham Hotspur in the EPL in Saturday, where he played on and scored the Gunners’ fifth goal in extra time.
He is now due to undergo a scan although Wenger said he expected Walcott to be sidelined for only a brief spell.
“The injury he got during the game with his shoulder, we have to scan that today and see if there is no damage. He will be out for tomorrow (Wednesday). It should be short-term,” Wenger said.