Frank Warren is hoping that Daniel Dubois’ newfound grit will be the difference when the heavyweight takes on Filip Hrgovic.

The two meet in Saudi Arabia on June 1 as part of the Queensberry versus Matchroom “5 vs. 5” card in Riyadh, Saudi Arabia. The IBF heavyweight title may also be on the line.

Dubois’ potential has never been in question, but it takes more than raw talent to succeed at the highest levels of the heavyweight division. If titles were awarded for athletic ability and genetics, fighters like Pele Reid, Micheal Grant and Seth Mitchell would be knocking on the door of the Hall of Fame.

Having raced through the first part of his career, the 26-year-old Dubois lost his unbeaten record to Joe Joyce, deciding to take a knee when the pain of a severely damaged eye socket proved too much. Then, maybe less understandably, he let a window of opportunity close and allowed himself to be counted out after he had unified heavyweight champion Oleksandr Usyk looking extremely uncomfortable following a borderline low blow.

Things came together when Dubois faced Jarrell Miller last December. After a strong start, it began to look like the pressure of the occasion and the effort of staving off a 333-pound opponent were beginning to tell on Dubois. But he found it within himself to fight through the fatigue and self-doubt, accelerating through the final stages of the contest and stopping Miller in the final round.

That newly demonstrated mental resolve will be needed against Dubois next opponent. Hrgovic, a confident, unbeaten Croatian, wasted little time in reminding Dubois how a previous sparring session between the two had gone and will be keen to evoke those memories as soon as the first bell rings in Riyadh.

Warren believes Dubois (20-2, 19 KOs) has the beating of Hrgovic (17-0, 14 KOs), provided the determination he showed against Miller is now a permanent part of his makeup.

“He’s got everything, Dubois,” Warren told BoxingScene. “The one thing people have questioned is that true grit. He showed it last time and, to be fair to him, he showed it against Kevin Lerena when he got clipped and his leg went. He showed some balls to get back into it.

“If he can show some grit, I think he wins the fight. It’s down to him gritting his teeth, going out there and being the governor and using his advantages.”

As Warren was talking, an example came to mind.

Being a stand-up boxer with a telegraph pole for a jab, plus a tremendous right hand, Dubois has drawn many comparisons to Frank Bruno. Bruno was also saddled with a reputation as a flawed fighter, for whom things would go wrong on his biggest nights.

Having come up short in three bids for the heavyweight crown, Bruno, in 1995 followed his pre-fight plan to perfection. He used his physical attributes and ability to build a wide lead over WBC titleholder Oliver McCall, and then relied on heart, grit and character to survive the final rounds and – finally – become a world champion.

“Bruno didn’t have a bad chin,” Warren said. “He would get caught, and his arms would drop to his sides like it wasn’t in the script. When he won the title against Oliver McCall, George Francis and I went out to watch [McCall] against Larry Holmes. Larry was gone by then, but he’s one of my favorite fighters, and he was using that jab.

“I said to George, ‘Frank has got a good jab. Keep a high pace and use that jab. In the later rounds, he’s got to walk onto him. Don’t do what he’s done in the past, where he gets clipped at the end. McCall doesn’t fight too well inside, so walk onto him.’”

Bruno’s flaws were physical, but the comparison holds up. Against McCall, an experienced Bruno put things together. If Dubois can combine his undoubted attributes with the mental strength and the self-belief he has proven he possesses, Warren believes he can beat Hrgovic.

“He has got a great jab, he can punch and he’s just gotta keep working,” Warren said of Dubois. “He’s got a good chin – although got stopped by Usyk. Maybe he got disheartened because of all that went on with the referee that night, but that’s not what it’s about. It’s about gritting your teeth and getting it done.”