The former England international was offered an extra year to stake his claim for a starting place at Anfield but the offer of a fresh start with Tottenham proved too tempting for Redknapp.
Redknapp said: "It is a big test for us and a big test for them as well but whatever the case, I'm looking forward to going back there again.
"I still owe Liverpool a lot. At the end, they actually offered me another year's deal but I thought I wouldn't be playing much and took the Spurs option instead.
"I think they respected it because I got a standing ovation when I played there last season and it was quite emotional."