By Rick Reeno

Las Vegas - Abel Sanchez, the head trainer of WBA, IBF cruiserweight champion Murat Gassiev (26-0, 19 KOs), believes his boxer's punching power is the difference in the upcoming unification with WBC, WBO champion Oleksandr Usyk (14-0, 11 KOs).

The final bout of the World Boxing Super Series cruiserweight tournament, is scheduled for July 21 at Olympic Stadium in Moscow, Russia.

"I'll tell you this, I have a big fight on September 15th with Golovkin and Canelo, I have another fight in the fall with Alex Saucedo and Maurice Hooker. That fight with Usyk, I see that as the toughest of the three," Sanchez told BoxingScene.com.

Usyk, an Olympic gold medal winner with an impressive amateur record, is the favorite.

"It's a very tough fight. I think the difference might be the power [of Gassiev]. If Usyk is stupid enough to hang in there too long - he could get hurt or might get knocked out. Usyk is an exceptional fighter. This a very difficult fight for both fighters," Sanchez said.

Back in January, Usyk was taken to his physical limit when he won a very close twelve round majority decision over undefeated Mairis Briedis.

Sanchez is not focusing on that performance. He's very confident that Usyk will never fight Gassiev in the same manner that he fought Briedis.

"In his last fight, the way he fought against Briedis.... I can guarantee you that he won't fight that way against Gassiev. He fought that way against Briedis because he didn't think Briedis could do anything to him," Sanchez said.

"A lot of these guys, when they don't perceive a threat - they fight in a different style. When Gassiev fought Dorticos, for the first four or five rounds, we let Dorticos throw his punches to deplete him a little bit. But Usyk, I don't think that he's going to allow Gassiev to beat on him for four or five rounds."