Reports emerged on Friday morning that the Spurs chief might cancel the proposed world-record transfer following Chelsea's attempt to hijack the north London club's move for Anzhi Makhachkala attacker Willian.
|10/1||Spurs are 10/1 with Bet365 to win the FA Cup
"That's a certainty to happen," the QPR boss told TalkSPORT. "Now they've spent all that money there's no way they'll pull the plug on that deal.
"And the boy wants to go. We all know that for a fact."
Tottenham have spent almost £60 million this summer on four new signings, breaking their transfer record twice, and Redknapp believes that they have a squad capable of challenging for the title.
"Tottenham have bought some fantastic players," he added. "You look at their squad and there is no reason why they can't be challenging to win the league.
"It really is a fantastic squad they have put together."