Barcelona's stand-in coach wants to leave the Copa del Rey semi-final controversy behind him and concentrate on Sunday's league match against Valencia
Dani Alves was supposedly subjected to racist chants, while Messi was alleged to have called Aitor Karanka "Mourinho's puppet" after the final whistle.
But Roura refused to comment on the Clasico incidents, insisting he is concentrating on this weekend's encounter with Los Che.
"The team is only focused on Sunday's match. I will not comment on other issues, I only want to talk about football," he told reporters.
"The Mestalla has always been a tough place for us to go, particularly in the past four or five years, and they are in good form at the moment.
"The Clasico game won't affect us, we are focused on Sunday."
Roura also confirmed Sergio Busquets would be ready for the game.
He added: "He [Busquets] had a small problem, but he's been training normally and he will be available."
Barcelona are top of La Liga while Valencia are seventh.