The midfielder had been doubtful with an ankle injury that he picked up in Saturday's defeat to Chelsea.
Former Manchester United goalkeeper Roy Carroll was expected to start for the Greek side but has instead been overlooked in favour of Balazs Megyeri.
Arsenal: Mannone; Jenkinson, Koscielny, Vermaelen, Gibbs; Coquelin, Arteta, Cazorla, Oxlade-Chamberlain; Gervinho, Podolski
Subs: Shea, Santos, Djourou, Arshavin, Ramsey, Walcott, Giroud
Olympiakos: Megyeri; Paulo Machado, Contreras, Manolas, Holebas; Maniatis, David Fuster, Siovas, Diakite; Greco, Mitroglou