Sydney: Michael Phelps issued a warning to his rivals at the Shanghai world championships on Friday, claiming that a change in attitude has brought the "old feeling" back to him.
"I felt like you had to twist my arm to get into the pool," the 14-time Olympic champion told reporters after a team training session on the Gold Coast.
"I was like kicking and screaming not wanting to go to the pool. This year has changed a lot... I can`t stand to lose, so I had to change something.
"I needed to get out of that funk when I did because if I didn`t, I think it would have been too late," he said after the US team`s training session at Gold Coast.
After nine years of dominating the pool, Phelps is grappling with a prolonged slump in form, having lost his pet 200 meters butterfly event three times this year.
The 26-year-old American noticed a similar hunger in Australian Ian Thorpe, who is on the comeback trail ahead of next year`s London Olympics.
"He (Thorpe) is somebody who is super-talented and when he retired (in 2006) I didn`t think it was true and I didn`t think it was real," Phelps added.
"But obviously he found a hunger to want to come back and want to do it again and I think it`s going to be even better for the sport.
"He`s the kind of person who if he wants to do something he`s going to make sure he will get it done," Phelps added.
The pool competition at the world championships runs from July 24-31.