Barcelona coach Pep Guardiola says form goes out the window for tonight's Copa clash at Real Madrid.

He knows form will have no bearing on Wednesday night's Copa del Rey quarter-final first leg against Jose Mourinho's Primera Division leaders.

"Going to the Bernabeu we must be wise to get through," he said at his pre-match press conference.

"The only way to get a result and have the tie alive is to go to win the game.

"Madrid are the strongest opponents that we can find. Against Madrid you cannot feel a favourite.

"In sport there are no precedents. It matters what you do at the time.

"Tomorrow is a new day and 90,000 people will support a team in white. You have to start again. That's the beauty. This work makes sense because it offers passion."