Petr Cech is poised for a Europa League SOS on Thursday with David Ospina's availability for the showdown against CSKA Moscow shrouded in mystery.
Arsene Wenger insisted he had a fully-fit squad going into Thursday night's clash at the Emirates Stadium.
But sources have indicated that Ospina is carrying a slight injury which may open the door for Cech, who missed Sunday's win over Stoke with a minor groin problem.
Intriguingly, though, it is understood Ospina feels he is fit enough to start against the Russians on Thursday.