Premier League - Van der Vaart: Harry must stay at Spurs
Redknapp has just a year left on his current deal and has reportedly hired Wayne Rooney's agent, Paul Stretford, to negotiate an extension.
Stretford and Spurs chairman Daniel Levy have reputations for striking hard bargains and it remains to be seen what length of contract 65-year-old Redknapp will be offered.
Van der Vaart has suggested it should be a long-term deal, insisting sustained success was linked to stability.
Asked if it was crucial Redknapp signed on, the 29-year-old said: "Yeah, I think so. He is doing a fantastic job, so I don't see any problems.
"I think he's going to sign a new contract - I hope so - and I think it's also good for every team when they have a manager who's there for many years. So I hope he stays."