Arsenal manager Arsene Wenger has confirmed that Aaron Ramsey will miss Tuesday's trip to Schalke through injury.
Ramsey was forced off with a groin strain during Arsenal's 2-1 defeat to Manchester United on Saturday and has failed to recover for Champions League duty in Germany.
The Welsh midfielder's place in the 18-man squad to face Schalke has been taken by Swiss defender Johan Djourou.
Wenger also revealed that Theo Walcott will make the trip to Gelsenkirchen but may not be fit to start after being taken ill overnight.