Theo Walcott has been ruled out of Arsenal's Champions League match against Montpellier on Wednesday night with a shoulder problem.

The England striker sustained the injury during Arsenal's 5-2 derby win over Tottenham at the weekend but was able to play on and scored the Gunners' fifth goal in injury-time at the end of the match.

Arsenal boss Arsene Wenger revealed Walcott had not trained Tuesday and would have a scan to determine the extent of the injury although he thought it would be short-term.

Gervinho is back in the squad for the game at Emirates Stadium.