Arsene Wenger says Arsenal can still reach the Champions League's knockout stage despite opening their campaign with back-to-back defeats in Group F.
Arsenal have progressed from the group stage in each of the last 16 seasons, but after losing their opening match 2-1 at Dinamo Zagreb, they lost 3-2 at home to Olympiakos on Tuesday in a game Wenger had said was a must-win.
They now face a double header against group leaders Bayern Munich, with Pep Guardiola's men visiting the Emirates Stadium on Oct. 20 before Arsenal travel to the Allianz Arena on Nov. 4, and Wenger knows they need points from those games.
Asked if it was realistic to believe Arsenal can still qualify, he told BT Sport: "Yes, it's still possible, of course.
"It was a shock of course for the team and a boost for Olympiakos, but I must say as well that we put the effort in and everything went against us tonight."
He added at his news conference: "It puts us in a bad position but we are still in it. We have to think we can deal with Zagreb and Olympiakos, and we need a result in our next game away from home against Bayern Munich."
Arsenal have played Bayern eight times in the Champions League, winning two and losing four, with both victories having come in the second leg of knockout clashes from which the German side progressed.
Wenger, who defended the decision to select David Ospina for the match, denied that the defeat represented his worst night in Europe, saying losing the 2006 Champions League final to Barcelona was more disappointing.
"No. Sit on a bench in a European final and I will ask you the question after," he said.