Modric, 25, has been key to Spurs' recent success and has subsequently been linked with many of the top teams in Europe. Juventus and Inter are among the clubs said to have expressed an interest of late, and the player's agent, Mario Mamic, was forced to dismiss speculation in Italy on Thursday.
"These are just rumours," Mamic told Calcio Mercato. "Luka has a contract until 2016 and Tottenham have no plans to sell him. He has an excellent relationship with the coach, Redknapp, and only signed a contract extension with Spurs last summer."
Redknapp, asked about the midfielder in an interview with Croatian newspaper Sportske Novosti, reiterated that Spurs would not entertain any offers.
"I wouldn't want to sell him for £100 million," Redknapp said. "Not even for a billion. He's the hub of the team."
It appears the future is less certain for the rest of Tottenham's Croatian contingent.
Niko Kranjcar has expressed a desire for first-team football and, while he rejected a move to Werder Bremen in January and then scored match-winners in successive games against Bolton and Sunderland in February, he has not started a game since.
"Niko's a great player and a great guy, very polite, but the guy just has no luck," Redknapp said. "I don't want him to leave the club - he was fantastic last season - but we've got Gareth Bale out on the left of midfield.
"Believe me, he'll be back in the team. I don't know when, but he will be back."
Asked about suggestions Vedran Corluka could leave White Hart Lane, Redknapp said: "I adore Charlie. I would be sorry to lose him.
"He's a really upbeat guy, always does what I ask him, but unfortunately he suffered the injury in that stupid challenge from Flamini [at AC Milan] and it ended that great run of form he was in."
Goalkeeper Stipe Pletikosa added to the club's Croatian contingent when he joined on loan from Spartak Moscow, but he has made just one appearance for Tottenham.
Redknapp said: "Pletikosa has been really good in training, but what I would say is, 'What would you do in my position if you had Heurelho Gomes? Gomes is in great shape, and you can't play everyone."