Boss admits that player's performances have dipped but he has no intention of allowing his £8 million summer signing to leave the club to free up funds for attacking purchases
Spurs snapped up the creative Dutch attacker on transfer deadline day last August, taking the player from Real Madrid in a cut-price £8 million deal.
Van der Vaart quickly showed his quality at White Hart Lane, starring for Spurs during the first half of the season and has returned to goalscoring form in recent week.
It has been rumoured that Redknapp would be ready to allow the Dutchman to move to pastures new as he looks to generate considerable funds to bring a new striker to north London; however, the Spurs boss insists that he has no plans to part with the former Ajax and Hamburg man.
"There's no truth that we want to part with him," Redknapp told reporters.
"He's done great for us although he has tapered off after a hard season."
Van der Vaart should be a part of the Spurs side that travels to Eastlands to take on Manchester City on Tuesday evening, but Redknapp knows that, even with a win, a second Champions League campaign is extremely unlikely.
"It will take a miracle [to finish fourth]," added Redknapp.
"Roberto Mancini has got a fantastic squad - they're in a great position.
"They are six points ahead of us and they have a better goal difference by miles."