Athletic Bilbao boss Ernesto Valverde has insisted that his team 'must believe' that they can beat Barcelona in the Copa del Rey final.
The two most successful teams in the history of the competition will meet in the final at Camp Nou on Saturday evening.
Valverde has conceded that Bilbao are the underdogs, but has claimed that 'miracles do happen'.
"For us it is a unique opportunity. I am of no doubt that it is one of the most difficult challenges facing Athletic Club in its history," Valverde told reporters at a press conference.
"In any other place it would have been difficult against Barca. The feeling of it being a challenge has grown due to playing at Camp Nou.
"We need to make few mistakes because it is a one off game and we need to make the most of our chances. You have to believe in miracles because they can happen."
Bilbao lost to Barcelona in the 2012 Copa final.
