Athletic, whose record of 23 Copa titles is second only to Barcelona (25), are favourites heading into the semi-final second leg after earning a 2-1 lead from last week’s first meeting at Mirandes’ Anduva stadium.
However, De Marcos knows they can take nothing for granted against the third-tier side, who have already knocked out top-flight sides Villarreal, Espanyol and Racing Santander on their fairytale run to the last four.
De Marcos said in Marca: “We need to have a lot of respect because Mirandes have earned it. They’ve knocked out three Primera Division clubs and that hasn’t been by luck or accident. The (first leg) result is good, but we need to wait and see what happens tomorrow. We know that it will be difficult and, because of that, we are going to put all our effort into it.”
De Marcos also hopes his side’s fans can help send Athletic through to the final, recalling the semi-final against Sevilla in 2009 when the Basque side overturned a 2-1 first leg deficit with a 3-0 home win to progress through to the final on aggregate.
“They have to support and help us because we are strong at San Mames thanks to them. Even though Mirandes are a Segunda B side, we need the support of the fans, like in that semi-final against Sevilla.”