Barca have been struggling of late, given that they have also recently lost on two occasions to Real Madrid.
"We've been marching differently. When we march together properly, Barça are a very big team, but when we don't we're a normal team," said Alves.
"So it's all down to us and whether we go into the game in the right way or the wrong way, like we did over there. If we do that, we'll be out - but if we march together, we'll have a chance."