Former super middleweight champion Carl Froch was an interested observer of last Saturday's heavyweight fight between Oleksandr Usyk and Derek Chisora.

Usyk, an 2012 Olympic gold medal winner and former undisputed cruiserweight champion, was taking part in only the second heavyweight fight of his pro career.

He had a much tougher time than many had expected in winning a twelve round unanimous decision over Chisora.

Usyk (18-0, 13 KOs) is the WBO's mandatory challenger to unified world champion Anthony Joshua.

Joshua will first make a mandatory defense against the IBF's top man, Kubrat Pulev, on December 12.

Should Joshua win, then Usyk and his handlers intend to press for their mandatory shot.

After watching the action from last weekend, Froch would confidently back Joshua to overcome the challenge of Usyk.

“The pace and pressure from Joshua, and the combination punches. I think Usyk would struggle,” Froch told Sky Sports.

“An even bigger, heavier, more solid, fresher heavyweight like AJ – and he lands more effective shots on the target. I don’t know if that’s answered the questions for me. I’m not putting him up there with the top three heavyweights in the world.”

Joshua, also an Olympic gold medal winner, is a student of the game. He's already studied Usyk and his style of fighting very closely.

“I know to sit down on my feet and hurt someone. You’ve got to let them know that you’re there because all that pitty-patty stuff after 12 rounds? Sometimes people don’t respect that type of power," Joshua said.

“He uses his feet very well, and positions his hands well. You can’t hit him because his feet move so well. If you do manage to catch him, [the punches] are brushing off the gloves. What I’d do, as I have done already, is study him – from his footwork, his hand positioning, to his openings. Then I’d go to former people who have faced him and find out information on how to defeat him.”