Barcelona boss Xavi has admitted that a poor second-half performance against Manchester United on Thursday cost his side the chance to progress in the Europa League.
The Catalan outfit took the lead in the second leg of the knockout round playoff at Old Trafford, with Robert Lewandowski netting from the penalty spot to send the visitors 3-2 ahead on aggregate.
However, Fred levelled the scores on the night, and in the tie, early in the second period, before Antony came up with what proved to be the winner for the Red Devils in the 73rd minute.
Xavi has said that his side "lacked composure and patience" in the second 45 minutes, with 'small details' costing the La Liga leaders in the competition.
"I think we were worse in the second half, we lacked composure and patience. A single goal hurt us a lot. Today we lost because of the details," Xavi told reporters after the match.
"It's a big frustration, a pity because we were so excited. But we were facing a great opponent. They are strong physically. Their first goal hurt us a lot. We were able to make it 0-2, and we've had some chances, but we haven't been able to take advantage of it.
"The difference with last year is that this year we competed. We competed against Inter [Milan] and Bayern [Munich] and today against Manchester United. They are a great team and it is difficult to compete against them. We should come back stronger next year.
"We can't be proud of ourselves, but we competed against a great rival. It's a shame. They scored two goals today, and two goals in the first leg. In the first half, we were very good, in the second half we were not. It's a shame. It was an excellent first half.
"Now we have to compete for La Liga and the Copa del Rey. We have to try again, to compete. We have to learn from our mistakes in the small details. We have to compete better in those head-to-heads.
"We have to respond now. Next Sunday we have a game, we are in a very good position in La Liga and we have to keep on competing... We can't give up now."
Xavi also admitted that his side missed both Gavi and Pedri, with the midfield duo not featuring at Old Trafford.
Gavi was unavailable for selection due to a suspension, while Pedri missed the contest due to the hamstring problem that he picked up in the first leg of the clash with Man United.
"We have to recognise the absence of Gavi and Pedri, they are two important players for us, and the impact of their absence has been felt," added the Barcelona head coach.
Xavi insisted, meanwhile, that Ronald Araujo would be available to face Almeria on Sunday despite being replaced in the 82nd minute of Thursday's match with what appeared to be a muscular issue.
"Araujo will be available on Sunday. I took him off the pitch as a precaution," he said.
Barcelona will be bidding to return to winning ways in the league this weekend before travelling to Real Madrid for the first leg of their Copa del Rey semi-final on March 2.