Mikel Arteta saw his Arsenal side reach the Europa League quarter-finals despite losing at home to 10-man Olympiacos before declaring they must improve in the next round or be knocked out.

The Gunners were beaten 1-0 at the Emirates Stadium as Youssef El-Arabi scored against Arsenal for the third game in a row.

Recalled skipper Pierre-Emerick Aubameyang missed a number of good chances to kill off the tie but a 3-1 win in Greece last week was enough to see Arteta’s side through.

While Arsenal advanced, their performance left plenty to be desired, especially when it came to drawing a blank in front of goal.

Aubameyang was the main culprit, the striker back in the starting line-up having been dropped for Sunday’s win over Spurs due to a breach of pre-match protocol.

Arteta said ahead of the defeat to Olympiacos that he had held positive talks with his skipper and that the incident was now in the past.

“I hope it doesn’t,” he replied when asked if Aubameyang’s profligacy could have been as a result of a hangover from the weekend’s incident.

“We’ve moved on from that. He started the game today and we expect him when he does play that he performs at the level that he can.”