Cesar was replaced at half time of the goalless draw with Sunderland in midweek after sustaining a minor groin tear. Rob Green will continue to deputise if Cesar fails to recover, while strikers Bobby Zamora (hip) and Andrew Johnson (knee) are longer-term concerns. Aston Villa left-back Enda Stevens has been ruled out of the game in London with the ankle injury suffered during the midweek win over Reading. Eric Lichaj is set to replace the former Shamrock Rovers player as Villa look for a third consecutive clean sheet. Skipper and centre-back Ron Vlaar remains a major doubt with a calf problem but utility player Chris Herd is back in contention after recovering from a knee injury.