Redknapp is likely to give a debut to Gallas tomorrow, believing the Frenchman is ready to prove he is still a world-class defender.
Redknapp said: "William was a great signing. Watching William in training and in the friendly you can see his quality.
"You don't play for championship-winning teams or your country as many times as he has unless you're a top player. He's got pace, everything, he's a great defender. He'll be a big asset. I think he'll be a great signing for us."