Damian Dovarganes / AP

The Puerto Rican salsa band and Mexican mariachi act alternated control of the Mandalay Bay casino floor’s sound waves.

Those wearing green, white and red on everything from wigs to tennis shoes swapped out spots closest to the boxing ring with a smaller group waving red, white and blue flags.

The camaraderie will only last so long. Unlike Tuesday’s grand arrivals, one of the nationalities will take a step back Saturday night at the Mandalay Bay Events Center when Mexican star Saul “Canelo” Alvarez challenges Puerto Rican icon Miguel Cotto in a middleweight bout.

“Puerto Rico, I think we’re ahead in our rivalry,” Cotto told Tuesday’s crowd immediately upon his arrival. “We’re going to keep ahead.”

There’s a different feel around the last major boxing week in 2015. For the first time in several years, the big fight in Las Vegas pits opponents representing separate boxing-crazed countries with fans notorious for their patriotic fervor.

The Money Team merchandising is out; national team soccer jerseys are in.

It’s the first local installment of the storied history between the two countries in the ring since Cotto lost to Antonio Margarito in 2008 at the MGM Grand.

“Mexico vs. Puerto Rico, it’s going to be a war,” said Oscar De La Hoya, Canelo’s promoter as CEO of Golden Boy Promotions. “You’re going to get fireworks. You’re going to get passion.”

De La Hoya would know. He was involved in arguably the rivalry’s most significant chapter at the same venue where Cotto, who’s promoted by Jay-Z’s Roc Nation Sports, and Alvarez will clash.

De La Hoya suffered the first loss of his career to Puerto Rico’s Felix Trinidad at Mandalay Bay in 1999, a close defeat that was among the best selling pay-per-views ever at the time. It was one of the fights that instilled the importance of the series between the two countries to a young Alvarez.

“This is something that’s very personal for him,” De La Hoya said.

The stereotype of Mexican and Puerto Rican fighters is that they will never shy from coming forward and engaging. De La Hoya is doubling down on that style playing out on Saturday.

He’s recently gone after the retired Floyd Mayweather Jr. for bringing the sport down by being boring with a promise that Alvarez’s time at the pinnacle will be different — starting against Cotto.

No one accuses Cotto of not being an action fighter, and the 35-year-old is coming off of a trademark performance in June where he knocked out Daniel Geale in the fourth round to win his third straight.

And anyone who thought Alvarez was veering more into technician territory than heavy-punching brawler must reconsider after the 25-year-old starched James Kirkland via third-round knockout in May.

“He’s demonstrated he’s going to fight more aggressive,” De La Hoya said. “Instead of waiting for the opportunity, he’s going to make the opportunity happen. That’s the style he’s going to use now. It’s an aggressive style that is not only fan-pleasing, but one that’s going to overwhelm his opponents.”

Partially because of the language barrier with English-speaking media, Alvarez is reserved with reporters. He reverts most questions with an answer about wanting to satisfy his fans more than anything.

Nothing would make them happier than a victory over a Puerto Rican adversary.

“We understand obviously the magnitude of this fight,” Alvarez said. “We must consume that responsibility with hard training, and we must win.”

Case Keefer can be reached at 702-948-2790 or [email protected]. Follow Case on Twitter at twitter.com/casekeefer.