Arsenal forward Pierre-Emerick Aubameyang was at a loss for words after his missed opportunity against Olympiakos in Europa League round-of-32 action on Thursday.

The Gabon striker scuffed on a close-range shot in the last seconds of added extra time in Arsenal's 2-1 second-leg loss to the Greek club at the Emirates, eliminating the hosts due to away goals.

What was even more heartbreaking for Aubameyang was that he had scored a spectacular aerobatic goal minutes before that seemingly saw the English side through into the last 16.

"Very, very disappointing. What can I say? It is very, very hard. It was a tough game again," the club captain told BT Sport after the match.

"I don't even know [how I missed that chance late on]. I feel very, very bad. It can happen but I do not know how I missed this chance. I was tired, I had some cramps but it is not an excuse."

Arsenal had beaten Olympiakos 1-0 in the first leg and appeared to have done enough to squeeze through when Aubameyang struck in the 113th minute to cancel out Pape Cisse's 53rd-minute header.

But the visitors had the last laugh as Youssef El Arabi struck seven minutes later to delight the noisy contingent of away fans, with Aubameyang then missing a gilt-edged chance to force another twist with the last kick of the game.

As Olympiakos celebrated the win, Aubameyang was visibly emotional and shaken as he walked dazed on the pitch.

Arsenal boss Mikel Arteta offered his disappointment after the match but noted the loss couldn't be pinned to Aubameyang's late miss.

"It hurts, big time. 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," Arteta said. "I think we did a lot of positive things in the game.

"I think we created enough chances to win the game, but if you concede two set-pieces again in a tie like this, then you put yourself in big trouble.

"This is football and sometimes it is very cruel when the emotions are [high], then in another moment they're [low]. 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."

With Arsenal ousted from the Europa League, the team must now beat Portsmouth on Monday in FA Cup fifth-round play for any hopes of silverware this season. They have an outside shot of qualifying for Champions League next season, sitting at 37 points in the Premier League standings.

"I just want to concentrate now on lifting those players and getting back the belief, and convince them that there is still a lot to play for, and move on," Arteta said. "It's part of this sport that a big disappointment can happen and it happened tonight. We have to learn and react as a team and as a club."