Defoe has been linked with a move away from White Hart Lane this summer after scoring just four Premier League goals last term in a campaign which was hindered by injury.
However, after seeing the 28-year-old visit a fitness coach in France and complete a strong pre-season, manager Redknapp still has the England international in his plans.
He told the Sunday People: "Jermain did not have the best time of things last season and had problems with injuries.
"He only scored four league goals and he is a 16-17 goal a season player, no question.
"But he has looked fit and he has looked really sharp in pre-season and a lot of that is down to his own efforts.
"He went over to France to see a fitness coach and that really does seem to have helped him a lot.
"I am looking for him to have a big season for Tottenham. He is really flying at the moment."
Spurs' opening Premier League encounter against Everton was postponed this weekend due to the London riots, meaning they will get their campaign underway with a Europa League play-off visit to Hearts on Thursday.
Redknapp is already facing an injury crisis ahead of the Edinburgh trip, with absentees in his midfield incurring a selection headache.
He added: "I'm struggling in that area. Jermaine Jenas is injured and so are Sandro, Steven Pienaar and Tom Huddlestone.
"At the moment, I think only Luka Modric is fit to play in midfield. On top of that William Gallas and Ledley King are also out."