The former Canadian heavyweight champion, who went 19 rounds in two fights with Mike Tyson more than two decades ago, wants to return to the ring.
Ruddock says he made the decision after training in Jamaica.
"I got in such shape that I realized I wasn't in shape when I was fighting Tyson and all those guys," he told The Canadian Press. "Now I'm in shape. ... I'm in the best shape of my life. I'm stronger, I'm faster.
"We can rebuild him, gentlemen," he added with a laugh.
Ruddock has to find an opponent and get licensed by an athletic commission. But his spirit is more than willing.
"I'm looking for a fight like yesterday," said Ruddock, a vegan who weighs a trim 215 pounds.
Ruddock (38-5-1) last fought in October 2001 when he stopped Egerton Marcus in the 10th round to claim the vacant Canadian heavyweight title.
"I didn't lose it. I just left it," he said of the championship.
Ruddock plans to officially announce his comeback Saturday in an appearance at a fight card in suburban Mississauga at the Hershey Centre.
Logan (Cotton) McGuinness (16-0-1) of Orangeville, Ont., defends his NABA super-featherweight title against American Meacher Major (20-4-1) in the main event.
Ruddock said his career was derailed by a shoulder muscle injury, which affected his jab. He had already signed to fight Marcus so he went ahead with the bout.
"And then I decided if I can't protect myself with my left hand, then I'm going to give the game a walk. And I did give it a walk. But by training in Jamaica the last four years, I've rehabbed the left hand. It is as dangerous as it's ever been."
Ruddock, who divides his time between Toronto and Jamaica, is also fighting a court battle in Canada with a former business associate over a garbage compactor called The Boxer.
He says millions are at stake in the courtroom.
As for boxing, Ruddock says he has unfinished business in the ring. He fought an array of former or future champions like Tyson, Lennox Lewis, Michael Dokes, Mike Weaver, James Smith and Greg Page but never got a shot at the title.
"I'm not doing this for money, I'm doing this because I want to do it."
But he is realistic.
"If I go in there and I lose one fight, by any means, then I realize I'm off, I'm wrong and I'm going to give it a walk. This is a dangerous sport and I'm putting 100 per cent into it."
He hopes to get a few fights under his belt before taking on Canadian champion Neven Pajkic. After that, he has his eye on world domination.
"I'm very disappointed in the state of the heavyweight division right now," said Ruddock, who wants to become the oldest heavyweight champion.
"These guys don't have the panache, the style, the punching power."
Ruddock says he has no regrets about his fighting career, noting he only lost five times — two of those were to Tyson (both in 1991) and one to Lewis (1992).
He says he wasn't ready for Lewis, but he was swayed by a "good sum of money." The first Tyson fight was stopped prematurely, he believes. In the rematch, he had his jaw broken,.
"I look back at all of these fights to see where I went wrong and I really didn't do too many things wrong," he said. "But I realize now I could do much better."
The only other men to beat him were David Jaco in 1985 and Tommy Morrison in 1995.
As for his age, he says the number doesn't apply to him. Although his explanation why is somewhat fuzzy.
"That 48 is for humans. That is for people living as a human. I'm a spirit, OK? I'm living as a spiritual person where I use the spirit to train the body."