Carragher plays his final game this weekend.
He told liverpoolfc.com: "The best centre-back I played alongside was Sami Hyypia, I thought he was a great player for the club. We've had lots of players but it could also be a coach; we had Phil Thompson here, Benitez was brilliant at setting up defences. He brought my game on a lot in terms of playing at centre-back because that was his expertise - making a team solid. It's difficult to pick one person, I've had a lot of help from a lot of different people."