Former two division world champion Bernard Hopkins is cautioning Mexican superstar Canelo Alvarez to avoid taking big chances with WBO light heavyweight champion Sergey Kovalev.

Hopkins lost a lopsided twelve round unanimous decision to Kovalev back in 2014.

Canelo is moving up in weight, by two full divisions to 175-pounds, to challenge Kovalev on Saturday night at the MGM Grand in Las Vegas.

Canelo's last bout took place at the middleweight limit of 160-pounds, when he won a twelve round decision over Daniel Jacobs back in May.

Kovalev, who Hopkins describes as "dangerous, has the advantage in size and power in the contest.

“Canelo can’t gamble with this guy,” Hopkins said to Yahoo Sports. “You must be on him and be aware, even when Sergey is tired and you think you’ve got him, that that threat is still there. A puncher can lose everything else, but they don’t lose their power. Ask Michael Moorer, when he fought George Foreman.

“Canelo has to always be aware of the threat and can’t afford to make a big mistake because if he does, that could be it. Canelo has a very good chance to be successful in this fight if he doesn’t forget that threat and get careless. He’s a smart guy and I think he knows that, but that’s so important for him.”

Kovalev is close to the end of his career, while Canelo is in his prime. He was nearly derailed back in August, when mandatory challenger Anthony Yarde had him in serious trouble in the seventh round. Kovalev recovered and stopped Yarde in the tenth.

Hopkins does not expect Canelo to have problems with the weight, but cautions that he can't be a stationary target for Kovalev to punch.

“The least problem Canelo is going to have is fighting at 175,” Hopkins said.

“Canelo has to be on the move, because it’s hard to hit a moving target. I’m not talking about leg and foot movement, because they could get him worn down and possibly knocked out. I’m talking about him moving from the waist up. One of the guys who had the most difficult styles to time and hit, even though he was a little shorter [for a heavyweight] was Mike Tyson.

“Mike had those fast hands and the swivel of his waist was just incredible. His legs were in the same position, but his waist was moving and turning and as soon as you’d commit and go to punch, you’d miss and instantly go, ‘Uh oh,’ because you knew what that meant.’ He’d be right there in front of you, but he was making those movements and it was so hard to hit him. That’s important for Canelo.”