Spurs are now wrapping up deals for Real fullback Sergio Reguilon and attacker Gareth Bale, a former Tottenham star.
And Redknapp declared to Stats Perform News: "I would go and see if I can get Luka Modric back. Take both, Bale and Modric.
"It would be a big coup. Luka is still a great player. That would be wonderful. I still feel they need someone there. They have the attackers, but they need someone to deliver the bullets.
"This is where someone like Luka Modric can hit killer passes. They lack such a player."