Daniel Dubois needed 'toughening up' following his first defeat to Oleksandr Usyk, the IBF heavyweight champion's promoter Frank Warren says.

The 27-year-old has faced questions in the past over claims he quit in his TKO10 defeat to Joe Joyce in November 2020, taking a knee to avoid further damage to, what was later revealed to be, a fractured eye socket.

The manner in which Dubois (22-2, 21 KOs) was stopped by The Ring, WBC, WBA and WBO champion Usyk (23-0, 14 KOs) in August 2023 also saw him come under intense scrutiny.

Since then, however, Dubois has been on a tear, knocking out Jarrell Miller, Filip Hrgovic and Anthony Joshua, the latter two of which he was the underdog.

Now a champion and full of newfound confidence, Dubois is set to rematch Usyk on July 19 at Wembley Stadium with all the belts on the line, and though 'Dynamite' has promised to 'nail' the Ukrainian to the canvas, Warren reveals he thinks his man needed fortify his toughness following the defeat to Usyk a year-and-a-half ago.

Quizzed on whether he thought Dubois would wash his hands of the sport during a media roundtable in London, Warren said: "No. I felt he needed toughening up. I don't mean that disrespectfully.

"I just felt he needed to be... I'll give you an example. Anthony Joshua's a street guy, a bit like myself, where I come from. I come from a tough part of London when I was a kid. He's a street guy, Daniel's not a street guy. He was brought up in an environment where his dad, from day one, most of the kids were going to be boxers and they lived that life.

"They weren't out on the streets, they weren't doing the things that kids are doing in London and so forth.

"And I noticed with Daniel and [Joshua], when they were doing the face-offs and so forth, doing that round table, AJ was trying to impose himself, maybe not even knowing he was doing it, by saying, you show me some respect.

"It was going over [Dubois'] head. It was a little bit like when Evander Holyfield beat Mike Tyson, who beat 90 percent of his opponents before they got in the ring. He was a street guy, tough sod, but he couldn't at Holyfield because Holyfield wasn't that way.

"That was a bit like [Joshua vs. Dubois]. I think this has toughened him, especially the things that were said, to go out there, after people are saying that 'you're a bottle-job' to get in that ring and prove people wrong, that takes a bit of [bottle] to do, and he's done it.

In his wins over Miller and Hrgovic, which ended in respective 10th-round and 8th-round stoppages, Dubois had to show a lot of that extra toughness Warren alludes to.

Miller had never been stopped before Dubois fought him. The American gave as much as the Brit could take, landing clean, leaning and tiring his man out across 10 brutal rounds of action in their December 2023 battle before Dubois came through.

Hrgovic looked well on his way to a stoppage over Dubois when they fought last summer, but Dubois survived the Croatian's early onslaught, worked his way back into the contest and won the fight on cuts late on.

Warren says both opponents were purposefully handpicked by himself.

The 73-year-old adds: "The reason I picked Miller as an opponent, he was undefeated, and a tough b-----d, and more importantly because I knew mentally the press conference would be tough for him because that's the way Miller performs.

"You know, he's a bit of a bully and he'll try and get on top of you and stuff. And I want to see how he stood up to that, and he did stand up to it.

"The next one against Hrgovic, the reason I picked him was because he was also undefeated, he was the most avoided fighter in the division, no-one wanted to fight him, he was mandatory for more than two years. I felt, again, that would be a mental challenge for him as well as a physical challenge.

"He rose to the occasion. The first three rounds, three and a half rounds, were rocky moments for him. He was getting caught with that right hand quite a bit. But he grit his teeth, came through it and at the end of the day he did what he can do, which I know, if he catches you, you're in trouble."