With the MLS season ending in November, a number of clubs have been linked with loan moves for the Los Angeles Galaxy midfielder.
The 36-year-old trained with the club last winter and, although Redknapp was impressed with his spell at the club, the Spurs boss believes that his abundance of midfielders would pose a problem.
"I was so impressed with David as a person, as a player," Redknapp told The Daily Telegraph. "He was fantastic to have around the club, a class act. For any young player looking at him, he's a great role model. There was no attitude to him, no 'side'.
"The problem I'd have is that David would want to play regularly, and I couldn't guarantee him that at this stage.
"It's difficult: I have Aaron Lennon coming back, Rafael van der Vaart playing off the right. I have lots of options. I could play Gareth Bale on one side and Luka Modric on the other. Sandro is also looking like he could end up a top player. Then there's Scott Parker."
The White Hart Lane club travel to Newcastle United in the Premier League on Sunday.