The Spanish fullback told liverpoolfc.tv: "Fernando and Stevie are really important for us and they are probably our best players. But we have a really good squad and know we have other really good players too. We can still beat Manchester United without Fernando and Stevie.
"It will be a hard game for us, but it will also be tough for them. Their defenders have to play against players like Yossi Benayoun, Dirk Kuyt and Robbie Keane.
"This year is really important for us because we have a fantastic team with great players. I think we can be successful. We now have people like Robbie Keane, who is a really good player, and Albert Riera too."