Connal McDonald intends to upset Lucas Roehrig in their Zuffa Boxing debut on Saturday night, live on Sky Sports.

Roehrig is an exciting cruiserweight prospect, being expertly guided towards the top by former world champion George Groves.

But McDonald has underrated credentials. He is the Scottish titlist and was an experienced amateur. Notably in the unpaid ranks he beat Daniel Dubois in the final of the Great British Youth championships in 2014 when they were teenagers.

Dubois, of course, is now a formidable two-time heavyweight champion of the world.

"There was all this talk about his power, even at that age," McDonald told Sky Sports. "The win looks great now! But at the time I was very, very confident, borderline cocky."

He recalled: "I was a very different fighter when I was that age. When Daniel walked out he was massive, built like a superhero. I was 17 and he was either 16 or 17. I had the whole mindset of 'I'm going to smash him'.

"I was standing in that ring thinking: 'I'm going to school this guy, I'm going to smash him.'

"It was a tough fight. The one thing I can remember is he was easy to land on. I was landing quite a lot of shots. I definitely thought at the end of the fight, I definitely won but it was one of those things where looking back on it, it was a tough fight.

"But I never would have thought he would have went on to be [one of the world's best heavyweights]. You're talking Usyk and probably Daniel Dubois now. Just respect to him for what he's done."

McDonald warned Roehrig: "I've come a long way from then, I'm a different boxer but come fight night I'll be treating it the exact same.

"No matter who's in there I'm going to go in and win.

"I'll be ready to go."

Watch Roehrig vs McDonald this Saturday live on Sky Sports.