Modric has been the subject of intense transfer speculation in recent weeks, with Chelsea having a bid for the 25-year-old rejected by Spurs, and Manchester United also said to be interested.
And Redknapp has some sympathy for his star man's situation.
"I can understand how Luka feels in all this," Redknapp said in The Sun. "If anyone offers to treble your wages you'd be interested and Chelsea are a big club.
"Everyone wants Luka. Just ask Alex Ferguson what he thinks of him, ask Roberto Mancini at Manchester City - they all want him. He could play for Barcelona.
"Luka wants the chance to win things and he is ambitious. All I'll say is that we are too at Tottenham.
"It's early days in the transfer market and no one is more ambitious than our chairman Daniel Levy.
"Luka wants to know that we'll be right up there challenging next season and we are working hard to bring in couple of big signings that may convince him to stick with us. I hope so.
"I have sympathy for Luka and his character has shone through in all this. He's a fantastic bloke and a genius of a player. I'd just ask him to be patient."
