Mirandes has already eliminated topflight clubs Villarreal, Racing Santander and Espanyol to become only the third team below the second division to reach the last four.
But now the northern club, guided by daytime banker and forward Pablo Infante, faces perhaps its toughest test yet against its Basque neighbor. Bilbao is a 23-time cup champion that has won five of its last six games, with striker Fernando Llorente scoring six goals over that stretch.
"We're filled with hope, and a lot of desire because we know we're just one step away from the final," Infante, who leads the competition with six goals, said. "Let's see what we're capable of." The only other third-tier clubs to reach the semifinals were Figueres in 2002 and Deportivo Logrono, 81 years ago.
Mirandes coach Carlos Pouso said his club's chances of progressing were slim since a two-legged series favors the stronger team, but that his team would not change its approach.
"We're well prepared for the good or the bad. We're all implicated in this and the players believe in our ideas, so there's little more to say," Pouso said. "Our fans have helped us very much, they are the motor that pushes us on." The club was building an extra seating section to accommodate an extra 1,700 fans at its 6,000-capacity Anduva stadium.
Barcelona overcame Real Madrid in the quarterfinals but has slipped to seven points behind its fierce rival in the league standings after yet another draw away from home on Sunday.
Barcelona has dropped 13 league points in 10 games away from the Camp Nou this season, including the 0-0 draw at Villarreal. But in the Copa del Rey it has won all three road matches so far by a combined score of 12-1.
The record 25-time cup winner is without Andres Iniesta for the match at the Mestalla Stadium while forward Pedro Rodriguez may also miss out to injury. Defender Gerard Pique came off with a knee problem but trained with his teammates on Monday.
Lionel Messi was far from his best and failed to convert several opportunities he usually puts away.
"The message inside the locker room is of belief and confidence," said goalkeeper Jose Manuel Pinto, who will play in place of Victor Valdes as usual in the cup. "The team isn't tired. But it is difficult for things to work out perfectly every single day." Tuesday's game begins a rematch of the 2008 semifinals when Valencia emerged victorious.
