Errol Spence Jr believes Lamont Peterson is a better fighter with "more heart" than Kell Brook.
The IBF welterweight world champion makes the first defence of the title he took from the 'Special One', when he takes on Peterson in the Barclays Center, New York, on January 29.
Spence Jr will not have boxed for almost eight months when he takes on a former sparring partner, but 'The Truth' is expecting a tougher test than he got at Bramall Lane, when a serious eye injury forced Brook to retire in the 11th round.
"You're going to see the same Errol Spence that you're used to," said Spence Jr.
"I can't look ahead because I know how dangerous Lamont Peterson is. I've been in training camps with him and I know what he can do.
"I've seen too many fighters look down the road and get beat before they get to the big fight. I have to be 100 percent focused and hungry. I'm fully dedicated to this fight.
"Lamont can push me to even greater levels. I feel like he is a better fighter than Kell Brook and has even more heart than Kell Brook and he can bring out the best in me.
"I think it's going to start out as a boxing match, but as we go on, it's going to be a dogfight. We both have big hearts. I've never known Lamont to turn down any fight. Not a lot of people wanted to fight me."
Peterson has won world titles at super-lightweight and welterweight, but is best known in the UK for beating Brook's bitter rival Amir Khan in a 140lbs unification fight back in December 2011, only to fail a drugs test ahead of a proposed rematch.
The 'Havoc' spend 14 months away from the sport but has since won world titles, including the WBA 'world' welterweight title he won in February but has since given up.
Peterson will have been out for almost a year when he challenges Spence Jr but is confident he can handle 'The Truth'.
"You already know when I fight, it's a feeling-out process to start, but in my head, I'm ready to go," he said.
"It's going to get rough in the trenches and we'll see who wants it more. I knew six years ago when Errol was in my camp that we'd get to this point. I knew he would be a champion.
"For the most part, I've seen him improve and progress throughout the pro ranks and I believe he's going to keep getting better.
"I can't worry about people thinking that Errol is the next star in this sport. I believe that, but I can't worry about it. It is up to me and my team to come up with the right type of strategy and execute it."