Saul 'Canelo' Alvarez says he is a "thinking fighter" and will provide the biggest test of Gennady Golovkin's career when they meet in a highly anticipated middleweight title bout in Las Vegas on Saturday.

Canelo (49-1-1) will attempt to depose the undefeated Golovkin (37-0) as the king of the division when they battle for the Kazakh's WBA and IBF belts at the T-Mobile Arena.

The Mexican has worked his way up from welterweight and believes he has the ability to provide GGG with the toughest fight of his career due to his intelligence in the ring.

Asked if he will be Golovkin's biggest test, Canelo told Omnisport: "Without a doubt. I will be.

"I'm a fighter who's a thinking fighter, who can make adjustments, who has a 'Plan A' and more than that and on Saturday night you're going to see it. We're going to show all those attributes, all that talent.

"I've had a tremendous preparation. Everything went well, everything went accordingly, just fine-tuning some things here and there. I prepared myself specifically for Golovkin and we're ready for Saturday.

"I'm very confident of what I can do. I'm very confident because of the work and the training and everything I put in for this fight. I'm very confident as well that on Saturday, September 16th I'm going to come out with my hand raised in victory."

Trainer and ESPN expert analyst Teddy Atlas believe Golovkin is no longer the same fighter and may have been exposed in his last few fights.

"Two years ago I said Golovkin was too big and too strong. Since then Golovkin has declined and perhaps even been exposed as a one-dimensional fighter while Canelo has improved. There will still be danger in that right hand of Golovkin for the first six rounds, but if Canelo can avoid getting caught with the big shot I think he can outbox an older Golovkin and win a split decision," Atlas said to ESPN.