Well, this is gonna be a good game. I can say that confidently already. Valencia has very strong forwards who will get through the defense if there is a chance. Barcelona always has a tough time against these opponents. As long as Barca can maintain a strong back and the midfielders do what they normally do, they should be able to pull ahead and win the match. I wouldn't leave myself too vulnerable in the defense to attack. This team has quality strikers. After all this is where Barca bought Villa from.
All in all should be a good match. enjoy it