“Why?” James Toney says fiercely as, just a foot away, the once brilliant and intimidating boxer leans forward and stares at me. “You wanted me to stop fighting? Why? Why?”

I look at my favourite boxer, who used to be rated as the best pound-for-pound fighter in the world, and prepare to tell him the obvious reason. But, pausing first, I remember the compelling stir Toney created in the early 1990s. Before then, when he was still carrying a gun and selling crack on the outskirts of Detroit, Toney’s life seemed distorted by his violent past.

His father had repeatedly beaten his mother, Sherry, at gunpoint. When James was only one, his dad shot Sherry and left them for dead. But Sherry is an incredible woman and, even though James was troubled, she channelled his incoherent rage. She brought him to a boxing gym so that, if he wanted to fight everyone, at least he could learn how to do it properly.

I fell for the Toney story in May 1991, on a steamy night in Iowa, when he became the world middleweight champion on the banks of the Mississippi. He came from behind to knock out the undefeated and exalted Michael Nunn, the hometown favourite. Having lived up to his nickname of “Lights Out”, Toney screamed: “I told ya so!” to the stunned crowd of 10,000. At 22 he had become the youngest world middleweight champion in 50 years.

I was fascinated by his female entourage. His mother, the indestructible Sherry, wore a big black hat and flashing red fingernails. Sarah, his beautiful girlfriend and future first wife, did not look much like the psychology student she was in that heaving ring. Jackie Kallen, his manager, was a middle-aged suburban white woman whose Jewish faith was honoured by the yellow Star of David on Toney’s black trunks. “Oh my God,” Kallen cried as she held a glowering Toney, “you did it.”

Intrigued by these contrasts, I tracked down Toney and his team. We forged a surreal friendship and, while following him for five years, Toney allowed me a privileged insight into his world – whether it was at home or being with him in the last anxious hours before world title fights, in hushed dressing rooms and even walking together to the ring. Toney was the dark star of a book I wrote about boxing. Dark Trade included other fighters such as Mike Tyson, Oscar De La Hoya, Chris Eubank and Michael Watson – but Toney meant the most to me.

James Toney lands a right on Evander Holyfield during their heavyweight fight in Las Vegas in October 2003. Toney won by TKO in the ninth round. Photograph: Jed Jacobsohn/Getty Images

Twenty-three years ago this month we were in Las Vegas. Toney was still ranked the world’s best boxer as he faced the similarly unbeaten Roy Jones Jr in a fight worth a $30m HBO contract for Toney if he won. In November 1994, lacking the discipline to stay in shape, Toney drained himself trying to make weight. He lost a unanimous points decision and was crushed.

It took him three hours to leave his dressing room but when he came to the after-party I admired him more than ever. I watched him being kissed by the old Jewish ladies, related to Kallen, and embraced by his homeboys. “Thank you for being here, man,” he said simply to me.

A few days later media outlets across America reported that Toney had threatened to shoot Kallen for having allegedly made him fight when he had flu and weight problems. His mother calmed him down and, slowly, he recovered. It took him a long time but he was named fighter of the year in 2003, when he outclassed the previously unbeaten Vassiliy Jirov to become world cruiserweight champion and moved up to heavyweight, where he totally dominated and stopped the once formidable Evander Holyfield.

Fourteen years later Toney is in Bristol and asking: “Why, why?” when I say I wished he had stopped fighting on the glorious night he beat Holyfield. My answer as to why I wish the 49-year-old was not even involved in an exhibition bout on Saturday night is clear. “I care about you,” I tell my old friend.

“I know,” Toney says. “I had 93 pro fights but tell me: Do I look like a punch‑drunk motherfucker?”

Toney’s face is bloated compared with the young middleweight I knew. But apart from some scarring he is relatively unblemished. He was also the best defensive fighter of the late 20th century and slipped punches better than any of his contemporaries. That was part of Toney’s appeal. Despite his profane and swaggering threats, he was a slick traditionalist who epitomised the art of hitting while not being hit. But, as his artistry faded and he became a fat heavyweight who barely trained, Toney absorbed damaging punches.

He is still amusing today – whether hollering my name as if he is Michael Buffer or telling me he could whip anyone if he put his mind to it – but there is no escaping Toney’s increasingly slurred speech. “I feel fabulous,” he insists. “People go on about my speech but I’ve always had a speech impediment.”

James Toney relaxes the morning after taking the IBF crusierweight title from Vassiliy Jirov in Mashantucket, Connecticut, in April 2003. Photograph: Reuters Photographer/Reuters

It’s true Toney always spoke with a slur but he is much harder to understand today. “How long you know me?” he asks. “Since 1991? Damn, we’re old now. But I’m the same motherfucker you knew when I was 24. I still think quick. I’m fast. I’m funny.”

I laugh and Toney whoops. “I’m funny as fuck. So why should I have stopped fighting?”

Boxing can cause brain damage and even death. No fighter is immune to the misery boxing can bring down if he remains in the ring too long. “But I’ve been fighting since I came out of the womb,” Toney says. “I’m the most natural fighter you’re ever seen. Floyd Mayweather’s a good fighter but he’s not as natural as me. Who is more natural than me? Please don’t say Anthony Joshua. I’m not a bullshit fighter and boxing ain’t like the 80s and 90s. I call it BSB. Bullshit boxing. Four fights and you get a title fight. I beat Nunn to win my title [in his 27th fight] on May 10 and my first defence was against [the accomplished] Reggie Johnson in June. Who does that now? Defend their title a month after winning it? I then went to Monaco and beat Francesco Dell’Aquila. My last fight that year was against Mike McCallum. Four world title fights in seven months.”

McCallum, The Body Snatcher, was a great fighter – and Toney describes him as the best he ever faced. “He taught me so much but I beat him in the fight of the year. Mike McCallum was complete. Before that we sparred at the Kronk [the renowned Detroit gym] and everyone knew you had a war or you died in the Kronk.”

Those gym wars took their toll but it’s hard to believe Toney will fight a local novice called Sam Pomphrey in Bristol. Pomphrey has had only two pro bouts, winning both in 2015, and he is a personal trainer rather than a fighter. Toney should avoid trouble but it upsets me that he is stepping inside a ring again – apart from the sadness of seeing him in a “white collar” bout.

I thought his last-ever fight had been in May when he beat Mike Sheppard, an old journeyman, in a promotion called The Final One? “It was my final fight. This one is an exhibition. Sheppard was a fight and I stopped him, boom, and went home. I’m in Bristol for some fun. It’s not a real fight. If it was a fight the price has to go up.”

Toney is still volatile and his mood suddenly changes. We’re sitting in an office with his manager, the gentle John “Pops” Arthur, and the Bristol promoter Matt Crouch. Toney points at Crouch. “Matt’s calling it a fight. If it’s a fight the pay’s got to go up.”

Pops shakes his head. “It’s not a fight. There are no licences, no medical examinations – so it’s an exhibition. You can have fun.”

Toney is unconvinced. “I came for an exhibition but they’re saying fight. If this is not a five-round exhibition where’s the money?”

“We signed for 10 rounds,” Pops explains. “We’re men of our word. We’ll stick to it. James is getting mad because it’s being promoted as a fight but Matt is just trying to sell tickets. James, if you want to be mad at anyone, be mad at your Pops. I negotiated this deal.”

“I don’t want to be played like a punk bitch,” Toney snaps.

I know Toney well enough to find a way to take the heat out of the office. “Everybody will love you on Saturday, James,” I suggest.

Toney relaxes. “Man!” he sighs, “I love England! I hate the fighters but I love the people. Where else can you get 80,000 people watching a fight like with Joshua and Klitschko? People here are so genuine.”

Toney has already told me he could probably beat Joshua if he put his mind to it but Pops would not allow him to take a proper fight again. So I ask who will win when Joshua and Deontay Wilder meet in an explosive world heavyweight title unification bout next year.

“Joshua. He’s much better than Wilder – who is wild. They’re good fighters but Joshua wins. I like Joshua. I like Danny Jacobs. That’s my guy, a good dude. Keith Thurman. He’s the truth. Triple G [Gennady Golovkin] is a good fighter.”

Everybody's a villain and I catch them. I go after criminals. I get to bust open heads for real James Toney

Toney is less enthused by Donald Trump. “He’s a fucking asshole. Remember when he was a promoter and he had me and Roy [Jones] on the same bill in Atlantic City. I should’ve punched him in the face but my mom and Jackie stopped me. Trump pointed to me and was saying: ‘Call Whatsisname over here.’ I’m thinking: ‘Whatsisname? I’m your headline attraction and you can’t say my name?’ I said to Trump: “I’m going to bust your head open, motherfucker.’ My mom and Jackie pulled me away but I should’ve knocked his head off and saved the world lots of trouble. He’s the president but he’s a racist. Look at Colin Kaepernick.”

Kaepernick, the former quarter-back for the San Francisco 49ers, has led a restrained protest against racism by taking a bended knee rather than standing for the national anthem. He is now locked out of American Football. “That’s why Colin Kaepernick hasn’t got a job. Pure racism from Trump down.”

Pops shakes his head. “I was with the Bureau [FBI] for 24 years and I never seen it this bad. Trump has a way of promoting racism and lots of people can’t see it.”

More cheerfully, Pops and Lights Out tell me about their plans for a reality television show, starring Toney as a bounty hunter. “Everybody’s a villain and I catch them,” Toney beams. “I go after real criminals. Our stuff is not edited. I get to bust open heads for real.”

Pops confirms Toney is now working as a part-time bounty hunter. “He knew this bounty hunter guy called Lucky. James did some dry runs and we took it from there. A cable company’s now talking about a 13-show season.”

I’ll be happier if Toney is a bounty hunter rather than a fighter. Those amazing days have gone and it’s a relief to hear him say: “I’m happy. I’ve got five kids and life is sweet.”

We call his mother in Michigan and leave a message because, as Toney tells me: “My mom will kill me if she don’t speak to you.” We go out into the gym, walk straight past the ring and Toney is chortling and hugging me. “We had fun again, man.”

I kid around and tell him he is still the king. “Say it again, man,” Toney hollers as his new girlfriend laughs.

“You’re still the king,” I say to the great old fighter.

“Twenty-six years,” Toney says with an incredulous smile, “and you still know it.”