By ESPNSTAR.com staff
Despite setting the footballing world alight with their double victory over Manchester United en route to the final, Bielsa's men failed to spark on Wednesday's night loss to Atletico Madrid, condemning them to runners-up status in the Europa League.
Atletico Madrid's Radamel Falcao struck twice in the first half to dent Athletic's hope of a first major European trophy before Diego killed the game off with an excellent individual effort late in the game.
Bielsa, who was often credited with reinventing Bilbao with their new-look Barcelona-esque pass and pressure style, claimed responsibility for a poor performance where they failed to make Atletico work.
"I feel tremendously disappointed," Bielsa is quoted as saying by Uefa.com. "We didn't play well.
"We played how Atletico wanted us to, allowing them to play their way in the process. Obviously, I'm responsible for how my team played and we did not accomplish our goal.
"Our opponents were deserving winners. There was a stark difference between the teams."
However, Bilbao's season is far from over as they have a Copa del Rey final against Barcelona in two weeks' time.
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Goalkeeper Gorka Iraizoz urged his team mates to not dwell on the defeat and focus on making amends against Barcelona.
"In 15 days we have another final," the goalkeeper told reporters after the match,"We have made it to two finals, which is something few teams do, and although tonight it is difficult.
"We now have to grit our teeth and, with the support of our fans, hopefully re-emerge in the same way Athletic have done many times before.
"We must go on. We must believe in the work that is being done and be proud of the way in which we got here.
"What we have to do now is to stick together; to be united. We know that we have another chance and we must cling to that now."