The 29-year-old striker has slipped down the pecking order at White Hart Lane, and as a result has been linked with a move away from north London.
Defoe has started just seven Barclays Premier League games for Spurs, but Redknapp is adamant that the England international remains an important part of his plans, and is unavailable for transfer.
Recent reports have suggested that Liverpool are planning a January bid, but Defoe insists he is focused on Tottenham, and says that whilst he is keen for more game-time, he is not targeting a transfer.
"At the end of the day it's not a case of me saying I want to go here, I'm not playing, I want to leave the club," he told Sky Sports News. "I've been here six years, I've never said that once. I think the fans know that.
"It's just a case of me playing. I could understand if I was 19, 20 and I had time on my hands but I'm 29 now and, like I've always said, all I want to do is play football. It's as simple as that."
Defoe's demotion has in part been down to the fine form of Manchester City loanee Emmanuel Adebayor, but the Togolese striker will be ineligible for Tottenham's trip to the Etihad Stadium this weekend, which could open the door for the Englishman.
"As it stands I'm a Tottenham player and if I do play against Manchester City I'll be fully committed," Defoe added. "I'm sure everyone knows that at the club."
Spurs head to the Citizens in third place in the Barclays Premier League, with a realistic shot at winning the title this year, having not won the domestic crown since 1961.
"I'm going to say what the manager says - it's not impossible," concluded Defoe. "I think when you really believe anything is possible - the way we're playing is fantastic.
"The chances we're creating, the intensity we're playing at, the way we move the ball; it's just been great. It's a good time to be at the club, everyone is enjoying it."