"I think it's important to have the centre-backs fit, but in this case it's not just the player and his position, it's also the character he has," said Benitez.
"We want all the players available, but especially players like Carra because he has the kind of mentality which helps other players.
"I knew he was good before I arrived because my Valencia team had played against Liverpool. I knew all the players but it was clear watching him with his teammates how important he was.
"He has passion, which adds something to the team in every game and every training session."