Arsenal captain Cesc Fabregas has apologised for his mistake in his side's UEFA Champions League defeat to Barcelona.
The midfielder, who passed a fitness test to play at Camp Nou, carelessly gave the ball away on the edge of his own box to help Barcelona score the opening goal of the game through Lionel Messi.
Fabregas attempted a back-heel to Jack Wilshere 30 yards out, only to give the ball away to Andres Iniesta, who in turn fed Messi who brilliantly lifted the ball over Manuel Almunia before smashing it into the net.
Arsenal were gifted an equaliser after the break when Sergio Busquets put through his own net before the visitors had Robin van Persie controversially sent off for playing on after the referee had blown his whistle for offside.
Barcelona made their numerical advantage count with Xavi making it 2-1 before Messi grabbed his second of the contest from the penalty spot.
Fabregas described the mistake as 'the worst moment of his life' and he took full responsbility for seeing Arsenal's European dreams end at the hands of Barcelona for a second successive season.
Writing on his social networking website, Twitter, Fabregas said: "Great support from the Arsenal fans. I take full blame for the result tonight.
"One of the worst moments of my life. I apologise."
Wilshere, who was one of Arsenal's best performers at Camp Nou, has tried to rally his team-mates ahead of this weekend's FA Cup quarter-final showdown with Manchester United.
Wilshere wrote on his Twitter feed: "We have to pick ourselves up now. Win Saturday and then keep going strong in the league... still could be our year."