Zubizarreta acknowledges there is great interest in the clash with Madrid, but is confident Pep Guardiola's men will be focused solely on their European challenge.
"It's true that since we started the season it seems everyone has been waiting for this game (against Madrid), but the clasico would mean nothing without all the other matches," he said.
"The Champions League is a vital part of the season for us, and so this game is very important for qualification, for first place and everything that happens later in this competition."
He added: "I've never seen this team hold anything back. They like competing. They are very good at focusing on the important aims. The game with Almeria was a good example of that, if you don't get caught napping in the league then it's difficult for that to happen in the Champions League."