IBF, IBO, WBO, WBA heavyweight champion Anthony Joshua views Derek Chisora as a very dangerous opponent for Oleksandr Usyk.
Usyk, a former undisputed cruiserweight champion, is taking part in his second fight as a heavyweight when he faces Chisora on May 23rd at the O2 Arena in London.
Usyk made his heavyweight debut last October, when he stopped very late replacement Chazz Witherspoon.
When rising up in the ranks, even as an amateur, Joshua regarded Chisora as one of his heroes.
He's sparred with Chisora in the past and says the durable boxer is very physically strong.
Usyk is the WBO's mandatory challenger to Joshua, who already has a fight lined up against the IBF's mandatory, Kubrat Pulev.
If the same Chisora shows up that gave Dillian Whyte all sorts of hell for twelve rounds, then Joshua expects Usyk to have a tough night ahead of him.
"The Chisora from the two fights against Dillian will give Usyk problems," Joshua told Sky Sports.
"I watched the Chisora versus Price fight - I thought: 'why isn't Price controlling Chisora?' Then I sparred Chisora. The guy is strong, you know. He is no joke. And I give Dillian credit for dealing with him twice. To control Chisora over 12 or 11 rounds takes some doing.
"For Usyk, who is a cruiserweight? Yes, feet and movement [work work against Chisora]. I was big enough to do that to Andy Ruiz Jr, to make him feel the power. Ruiz Jr knew that if he walked in without thinking about it then he might catch something. When you're dealing with someone and you're not worried about their power, i.e Chisora may not be worried about Usyk's power, then Usyk may run into some problems. Then again, Usyk is one of the best fighters the world has ever seen in this generation."