“He went from Jarrell Miller, Filip Hrgovic, Anthony Joshua – three dangerous hard fights and he has come through them all with flying colours, so I think anybody that doubted him or had any questions over stuff that happened to him in the past, it has all been answered now.”

Campbell has boxed with a number of the world’s leading heavyweights and believes the ruthlessness of Dubois is something that stands out.

“I have sparred Tyson Fury, I have been with Joseph Parker for a few camps, I have been in with Agit Kabayel and Martin Bakole, so I have sparred a lot of the boys in the top 10,” he said.

“I get asked this question a few times – who is the biggest puncher you have ever been in with? And, in sparring, it is probably Daniel Dubois. I’ve shared probably over 50 rounds with the guy in the last two camps so I know how hard he can punch.

“But I will caveat that by saying Daniel’s mentality is that when you are in there, his job is to seek and destroy – it is a one-track mindset with him.”

Campbell pointed out that Dubois is not just “a hell of a puncher”.

“He is a good boxer, he has got great feet, which doesn’t really get spoken about, he has got a good boxing brain, he has got a fantastic jab,” he said.

Campbell took up boxing as an amateur in 2017 following a top-level rugby career with Glasgow Warriors and Jersey Reds.

Since turning professional in 2021, he has won six of his seven fights and will return to the ring in Birmingham next month brimming with renewed “confidence” from being asked again to spar with one of the world’s best.

“Don Charles, Daniel’s coach, said to me, ‘you need to use this as a springboard for yourself – you need to have this known that you have been in there and shared the ring with somebody of Daniel’s class and calibre’,” Campbell revealed.