By Luke Furman

Cruiserweight contender Murat Gassiev (23-0, 17KOs), 23-years-old and trained be Abel Sanchez, is one of the best rising talents in the sport.

On Saturday, December 3rd in Moscow, he will challenge countryman Denis Lebedev (29-2, 22KOs) for his WBA and IBF world cruiserweight titles.

Gassiev is regarded as one of the biggest punchers out there and he is often used as a sparring partner by some of the best heavyweights out there.

Current WBC champion Deontay Wilder and former division ruler Wladimir Klitschko are among the heavyweights who have retained Gassiev's services.

The Russian slugger says Wilder is a harder worker, a bigger puncher and has a difficult style to figure out.

"Klitschko is a very clever boxer, he's very smart in the way that he uses his long arms, his height. He just keeps his left out. To those who are shorter, it is impossible to get close to him. He has a very discreet right jab. You simply do not see it, it appears out of nowhere. But I would not say that his jab is super-strong - just a good, strong punch for a heavyweight," Gassiev told Match TV.

"Wilder is the hardest worker I've been in with. [He's the hardest puncher], in addition he has dangerous angles to his attacks that are difficult to understand. If Klitschko has a classic technique, then Wilder is very unusual and his attacks are very difficult to defend against. If you look from the outside, the movements seem clumsy, but in the ring they work in a very efficient manner."

"Outside of training, Wilder plays the fool, laughs.... but when it comes down to it he is completely focused and works to the maximum. He disconnects from his jokes, so he prepares very seriously."

Luke Furman covers boxing for bokser.org.