Mikel Arteta has called on his Arsenal players to "keep fighting" for the rest of the season after last year's finalists were dumped out of the Europa League by Olympiakos on away goals.
Youssef El-Arabi scored in the dying seconds of extra time to give the Greek side a 2-1 victory at the Emirates Stadium, meaning the last-32 tie ended 2-2 after the second leg.
Pierre-Emerick Aubameyang's acrobatic finish in the second half of extra-time appeared to have put Arsenal on course for qualification after Pape Abou Cisse's header had sent the tie into an additional 30 minutes.
But the last-gasp winner brought a premature end to Arsenal's European campaign and Arteta must lift his side for a push to qualify for the Champions League through the Premier League.
The club, unbeaten in the league since December, are ninth in the table, seven points behind fourth-placed Chelsea.
Asked about the difficulty of finishing in the top four, Arsenal manager Arteta said: "(It is) very hard because looking at the table we're still far from the objectives that we all have, but we've been far all season from it and we have to keep fighting.
"The most important thing now is that the dressing room has to be strong and we have to keep going and react.
"First of all, I have to convince them about what happened in the game and why they are not through in the tie.
"If they continue to do that, there will be rewards like we have done in the last 10 games that we played."
Arsenal had shown signs of improvement since Arteta's appointment in December but they were lacklustre for much of Thursday's match, having gone into the second leg defending a 1-0 lead.
"It hurts, big time," said Arteta. "We had a lot of hope in this competition. It was a great way for us to be able to go to Europe and it is a very beautiful competition to try to win."
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