The Basque side currently trail 2-1 from the first leg and the two sides met again just two days ago, in the Primera Division, with the Andaluz winning by the same margin at San Mames.
Despite the setback, one of the club's stalwarts, Joseba Etxeberria, is optimistic that his side can progress to the final, and then go on to lift the trophy.
“This is a match that will allow us to make history. If we can make it to the final, we will be champions,” he was quoted as saying by Marca.
“But in order to do that, first we must eliminate Sevilla, and that is not going to be easy because they are a great rival with a lot of experience in these games.”
When asked who will be the favourites to advance, the 31-year-old replied, “It will be a very open game and I don’t think either team are the favourites.
“It’s true that they have the advantage at the moment, but this game will be infront of our own fans and the atmosphere is going to pull us through. I am convinced that the fan support will help us and the pressure on Sevilla will show.”
Finally, Etxeberria discussed what his team would have to do to overturn the 2-1 deficit.
“It would be very important to score first and make it 1-0. That will change the complexion of the tie completely because Sevilla will then have to come out and play. And there is no bigger advantage for us than to be able to play on the counter at home,” he concluded.
This year’s Copa final could potentially take place between the two most successful clubs in the competition. Barcelona, who have won the cup 24 times, have a 2-0 lead over Mallorca in the other semi-final and are favourites to go through.
Athletic have also won the competition on 24 occasions, although there is dispute that under their present club name they have only won it 23 times.
KS Leong, Goal.com