Arsenal boss Mikel Arteta was left to rue missed chances as his side crashed out of the Europa League at the last-32 stage after losing on away goals to Olympiacos.

Despite winning the first leg in Greece 1-0, the Gunners lost 2-1 at the Emirates on Thursday night with Youssef El-Arabi scoring in the final minute of extra time to send Pedro Martins' side through in dramatic fashion.

Pierre-Emerick Aubameyang had a chance to win the tie in the dying seconds for Arsenal, but he put his shot wide from six-yards in one of many chances that Arteta was left to rue.

"I think as the game went on, we were getting better and better and they were playing deeper and deeper," he said.

"We generated more than enough chances to win the game and we shouldn't be talking about what happened now.

"I think we have enough goal threat in this team, but we have to put the chances to bed and in Europe it's in both boxes.

"In the opponent's box, we missed chances that should have been goals and in our box there were a few things that they had and they put them in.

"On the set-pieces we were vulnerable again so these are things to improve.

"Details are so important in ties. We gave details away that you cannot afford. Even if not in the opposition box, you have to be ruthless, and we weren't tonight."

Arteta is keen to move on after the disappointment of being knocked out, adding: "I've seen all the boys and I know how much they wanted this competition.

"I've seen today the way they fight and the way we try to play and it's a difficult one to digest as a team and as a club.

"This is football and sometimes it is very cruel when the emotions are right up high, then in another moment they're somewhere else.

"You have to able to handle that if you want to be in this industry so now it's up to us and up to me to bring this place back in and move forward."