Valencia coach Ruben Baraja is adamant they're capable of beating Barcelona today.
Baraja has called on the Mestalla crowd to make the difference.
He said: "If I were a fan, I would want to see the team putting pressure on the opposition and looking for victory, giving 100%. Tomorrow, in front of our fans and with what we are going to offer, we are going to make it difficult for Barça. We have to know where we come from and what the objective is.
"We must be able to maintain the serenity and tranquillity that we were able to convey last year. Above all, we have to support and push these players, who are the ones who have to excite us. We love them, most of them are from here and they are young players who need us.
"If you want to compete against Barça, with that individual quality that can make the difference from a single move, you must have a complete and intense game, keeping the contest alive until the last minute. You have to have clarity in the final metres. Barça's game ends up sinking you because they have the ball a lot.
"We must do many things well to compete -and sometimes even that is not enough. What motivates me most about this challenge is seeing my players with the energy that the game requires.
"Barça are always dangerous, both individually and collectively. They have speed and are great at one-on-ones. They are very complete, but we also have something to offer tomorrow."