LAS VEGAS — The big stage debut of teenage Mexican sensation Saul Alvarez highlights the undercard of the Floyd Mayweather-Shane Mosley fight on Saturday.

Alvarez (31-0-1, 23 knockouts), who will face veteran Jose Cotto in the televised main supporting bout to the Mayweather-Mosley fight, is by far the most advanced and celebrated of the many prospects that will be in action on the stacked undercard.

The 19-year-old native of Guadalajara, Mexico, is also one of the most popular fighters in his country.

“Alvarez is the new face of boxing in Mexico,” said Richard Schaefer, CEO of Golden Boy Promotions, which recently signed the fair-skinned prospect. “He has his own television deal with Televisa and his fights do equal ratings with the Mexican natioanl soccer team. Literally 15-16 percent of the nation watches his fights.”

With his fair skin, red hair and freckles, some — including Oscar De La Hoya — have jokingly called Alvarez “boxing’s Howdy Doody” (and truth be told, the kid does bare a facial resemblance to the cowboy puppet of the 1950s-era children’s show). The Mexican media calls him “the boxing James Dean.” His nickname is “Canelo,” Spanish for cinnamon — a reference to his fiery hair and ring temperament.

Alvarez is not all hype. The young man can fight and box, and he does so in an entertaining manner.

However, the trainer of Cotto, the battle-tested older brother of Miguel Cotto who was a member of the 1996 Puerto Rican Olympic team, believes the young man will be in over his head on Saturday.

The only blemishes on Cotto’s record (31-1-1, 23 KOs) is a decision loss to then-undefeated Juan Diaz in 2006 and a draw with Prawet Singwancha in 12-round title bouts. However, those fights took place at lightweight, the 32-year-old vet’s natural weight class. Saturday’s bout with Alvarez is at welterweight.

Cotto’s trainer, Mario Santiago, doesn’t believe size will matter.

“(Jose) came here to put on a great fight and get a great win, not to be a stepping stone for anyone,” Santiago said. “He will demonstrate that he belongs in the big leagues of boxing.

“All due respect to Golden Boy Promotions but they should do a better job of matching their up-and-comers. I hope Richard Schaefer and (Golden Boy matchmaker) Eric Gomez don’t lose their jobs after Jose wins.”

Santiago’s comment got a laugh from those who attended the Thursday undercard press conference that took place in the media center of the MGM Grand. Even Schaefer and Gomez chuckled.

Alvarez’s manager Jose Reynoso didn’t think it was funny.

“We don’t won’t easy opponents,” he said. “You have to beat good opponents when you are on the big stage in Las Vegas. Alvarez is well prepared so we’re not worried. The only good thing about Jose is his last name.”

Alvarez, who turned pro at age 15 after only 20 amateur bouts, is confident in his ability.

“I have a lot of respect for Cotto, who I am very familiar with, but I can adapt to any style,” he said. “I’m ready for him. I feel I’m ready to take on his brother.”

PROSPECTS IN ACTION

Two solid matchups between experienced pros will round out the pay-per-view-televised portion of the Mayweather-Mosley undercard.

The broadcast will kick off with a 10-round welterweight bout between Hector Saldivia (31-1, 24 KOs) and Said Ouali (26-3, 18 KOs). Golden Boy Promotions is very high on Saldivia, of Argentina, who is coached by middle champ Sergio Martinez’s trainer Gabriel Sarmiento. Ouali, a native of Morocco now living Las Vegas, is a tough and game southpaw who is part of the Mayweather Promotions stable of fighters.

Saldivia-Ouali will be followed by a 10-round featherweight bout between Daniel Ponce-De Leon (38-2, 32 KOs) and Cornelius Lock (19-4-1, 12 KOs). De Leon is an awkward, hard-clubbing southpaw puncher and former 122-pound titleholder. The 29-year-old vet has won four bouts since getting knocked out in one round by Juan Manuel Lopez two years ago.

Lock, who is trained by Roger Mayweather, is coming off an impressive fifth-round KO of previously unbeaten Orlando Cruz but was beat up in a 10-round decision loss to Antonio Escalante before that fight. DeLeon has taken on a new trainer, Dub Huntley, a middleweight journeyman during the 1960s who fought all-time greats Carlos Monzon and Luis Rodriguez.

Lock is a skilled, athletic southpaw with speed and good power. His stick-and-move style should trouble the more-experienced DeLeon. Huntley knows this but believes in the old adage “Kill the body and the head will follow.”
Four unbeaten prospects worth watching will be on the non-PPV portion of the undercard. All are worth keeping an eye on.

Junior lightweight Eloy Perez (16-0-2, 4 KOs), of Salinas, Calif., is the most talented of the up-and-comers. Perez, who battles Gilberto Leon (23-7-2, 7 KOs) in a 10-round bout, is a crafty and versatile boxer-fighter who makes for entertaining fights. Perez has his work cut out for him with Leon, of Mexicali, Mexico, who is not only more experienced but five inches taller.

Welterweight Jesse Vargas (9-0, 4 KOs) faces the most experienced opponent of his young career in former 140-pound title challenger Arturo Morua (25-13-1, 14 KOs) in an eight-round bout. Vargas, a native of Mexico who now calls Las Vegas home, is an intelligent pressure fighter who possesses a devastating left hook and body attack. The 20-year-old prospect, who is trained by Roger Mayweather, has drawn comparisons to a young Antonio Margarito.

Lightweight Luis Ramos (14-0, 7 KOs), an alumni of Golden Boy’s Fight Night Club series, takes on Allen Lizau (13-4, 7 KOs), featherweight contender Jason Litzau’s younger brother, in an eight-round bout. If Ramos takes care of business against Litzau fans can expect to see the talented Orange County-based southpaw graduate to Golden Boy’s new “Solo Boxeo” series on Telefutura.

Super middleweight Dion Savage (7-0, 5 KOs) fights Philadelphia’s Tommie Speller (5-3, 3 KOs) in an eight-round bout. Savage, who had a solid but not spectacular amateur career, is a strong and aggressive boxer from Flint, Mich., who is trained by Team Mayweather’s Nate Jones, a 1996 U.S. Olympian.