Three belt champion Golovkin will be the underdog when he faces Mexico's hard-hitting Alvarez on Saturday in a 12-round mega world title fight at the T-Moblie Arena.

"It is like you are going with your new girlfriend, Oh yeah," he said of his excitement about the fight for middleweight supremacy.

The 35-year-old from Kazakhstan told reporters at a news conference on Wednesday at the MGM Grand Hotel and Casino that he doesn't consider himself an underdog against Alvarez, who is eight years his junior.

"This is my game, my fight" he said. "I am the boss. I am the champion."

Golovkin has waited a long time to get his first fight on the boxing's biggest stage in the United States. He is undefeated with a 37-0 record and has fought in 22 cities and seven different countries but never in Sin City.

"The biggest day is coming. This is a true fight, there is a lot of money coming," Golovkin said.

Several years ago Golovkin hired a much younger Alvarez to be one of his sparring partners at a training camp in Big Bear, California.

So there is some familiarity between the two but Golovkin expects Alvarez to come into the fight with a few new wrinkles in his game plan.

"He might bring some new ideas to this fight. I am ready for anything," Golovkin said. "I am ready to fight. It is a first class fight."

Alvarez, who has only lost once in 51 fights (49-1-1), said he trained 10 weeks for this bout.

"I just want to say I am prepared. I know it is going to be a tough fight," Alvarez said.

Alvarez's trainer Eddy Reynoso said training camp was a success and his fighter is in top condition.

"We had a great preparation, more than 14 years to prepare for this fight," Reynoso said. "We had a great camp, no injuries, everything went well."

Golovkin's trainer Abel Sanchez said the two fighters' punching power will make for an interesting contest.

"We look for a dramatic fight, an explosive fight," Sanchez said. "These two guys have the styles that are going to give us a fight we will remember for a long time."

- Underdog motivation –

Golovkin might not want to admit it but Sanchez says that it bothers him that as the World Boxing Council, World Boxing Association and International Boxing Federation middleweight champion he is not favored to win.

"People are picking Canelo and that motivates him more."

Sanchez said Golovkin lost some of his popularity after his last fight in March because he had to go the distance to beat Daniel Jacobs instead of knocking the challenger out.

Sanchez says Jacobs is a better fighter than Alvarez.

"If Jacobs had fought Canelo that night it would have come out different," he said.

Tickets are sold out for Alvarez-Golovkin but Sanchez says they still have work to do to get people to buy the pay-per-view. He said boxing fans who shelled out $99 for the Floyd Mayweather-Conor McGregor novelty fight just over two weeks ago might be reluctant to buy this one.

"It might have hurt us a little but it didn't hurt as much as people thought it would," Sanchez said.

"A lot of casual fans would have bought this fight if they hadn't spent $99 on a spectacle."