Former Arsenal defender Martin Keown has criticised the team for their "unprofessional" performance in Thursday's Europa League defeat by Olympiakos Piraeus, which knocked them out of the competition.
Olympiakos forward Youssef El Arabi scored in extra time and sealed a 2-1 win in the round of 32 second-leg clash in London, as the Greek side progressed on away goals after the tie ended 2-2 on aggregate.