Redknapp admits he was hugely disappointed when the Hammers were relegated and hopes they bounce back quickly under new boss Sam Allardyce.
"It's so sad to see them down there but they have to go down, rebuild and come back again," he said. "They've done it before and there's no reason why they can't do it again.
"It's a fantastic club with fantastic tradition. They have great support; they live for that club those fans.
"It's a big loss that they went down but I'm sure they will come back. I just hope they do it quickly because it won't get any easier."