Arrasate, whose side travel to the Camp Nou off the back of a 4-0 defeat to Atletico Madrid, has also called on his side to "be more aggressive" against the Catalan outfit.
"That's our aim, to return to Anoeta with the tie still alive, so we can resolve things at home. If that happens, it will be great news for us," he told reporters at a press conference.
"It's not about them losing two straight games, because it could also be a draw, but what is obvious is that we'll have to be very good to overcome them.
"We have to be more aggressive, more solid and not give anything away against such a great opponent and who always play well, but without losing our spark in attack, which is our best facet."
The first semi-final will be contested between Atletico Madrid and Real Madrid.