But the Republic of Ireland captain has insisted he rediscovered his "hunger" for success while at Celtic Park.
He said: "Going to Celtic was maybe the best thing that ever happened to me."
"I am going back to Tottenham unless someone tells me different."
Keane, who has been linked with a possible move to Premier League rivals Aston Villa, added: "I have a three-year contract left and I am going back to train at Tottenham on July 5."
The Irishman has admitted that he lost confidence after returning to the north Londoners for a second spell in February 2009 after a disappointing six-month stint at Liverpool.
He failed to keep a regular spot in the Spurs starting line-up in the first half of the 2009-10 season and was loaned to Celtic this February for the remainder of the campaign.
"I did not have the hunger I had, and I certainly got that back at Celtic and got my life back on track and really enjoyed my football again," he revealed.
"It's up to me now to go back to Tottenham and get back into that team and stay in that team.
What do you think about Keane returning to Tottenham?
"Harry [Redknapp, Tottenham manager] knows what I am like and the type of personality I am. I just love playing football and he fully respects that."
Keane, who will lead his country in an end-of-season friendly against World Cup finalists Paraguay on Tuesday, added: "I love to play football and I am not one of those people like to sit on the bench and pick up the money and be happy with it."
He has also hailed Tottenham's "massive achievement" of breaking into the top four of the Premier League and so earning a shot at the Champions League.
Keane cost Tottenham £12m when he returned from Liverpool six months after the north Londoners sold him to the Anfield club for £19m in July 2008.
The striker, who joined Tottenham from Leeds for £7m in 2002, will face competition for a starting place from Peter Crouch, Jermain Defoe and Roman Pavlyuchenko next season.
Source: BBC Sport
Source: BBC Sport