Barcelona coach Xavi says they won't underestimate going to Rayo Vallecano tonight.

Xavi is wary of facing a partisan crowd in Vallecas.

"It's the most complicated match, playing on a smaller pitch than normal against the most intense opponent in the division -- in the good sense of the word," Xavi said.

"They are a very solid team who don't give a ball away, they are a very uncomfortable opponent. We have warned the players that they will be a very intense opponent, they don't let you progress, the distances are shorter, there will be a lot of rebounds, second balls.

"It will be a really difficult game, it won't be easy to play our game, we'll have to be more practical than usual."