Top 10 boxers aged 25-or-under

A year after Floyd Mayweather Jr.’s retirement and less than two months before Senator Manny Pacquiao’s return bout at age 37, it’s clear that boxing will require some youthful talents to replenish the sport.

By coincidence, some of the leading candidates to become the sport’s next big face are 26 years old.

That group includes Mexico’s junior-middleweight champion Canelo Alvarez, unbeaten heavyweight champion Anthony Joshua of England and rising welterweight Errol Spence Jr. of Texas.

Alvarez (48-1-1, 34 knockouts) secured his standing by drawing 51,240 to AT&T Stadium in Texas on Saturday, and there’s not a better pay-per-view draw in the sport right now.

But how deep is the young talent pool beyond that?

Already, there are some world-title belts being worn by young boxers who’ve shown dominating power and skills, along with a championship work ethic as they climb their way up the sport’s talent ladder.

Below is The Times’ top 10 list of boxers who are 25 years old or younger:

1. Naoya Inoue; Japan; super-flyweight; 11-0, 9 KOs;

Already a two-division champ at 23, Inoue is viewed as “a killer” by some of boxing’s smartest observers. He’s made three successful WBO title defenses and was mentioned by HBO’s Max Kellerman as the next best foe for new WBC champion Roman “Chocolatito” Gonzalez.

Next fight: He just fought Sept. 4, claiming a 10^th-round knockout in Japan, so there’s some rest and negotiation to come.

2. Oscar Valdez; Lake Elsinore; featherweight; 20-0, 18 KOs;

The 25-year-old former Olympian for Mexico won the WBO featherweight belt in July with a second-round technical knockout of Argentina’s Matias Rueda, a brief showcase of the onslaught of punches and fearless approach Valdez offers.

Next fight: Makes his first title defense Nov. 5 on the Manny Pacquiao-Jessie Vargas undercard against top-ranked contender Hiroshige Osawa of Japan.

3. Murat Gassiev; Russia; cruiserweight; 23-0, 17 KOs;

Abel Sanchez, who also trains unbeaten middleweight champion Gennady Golovkin, refers to the 22-year-old Gassiev as the “cruiserweight GGG.” Gassiev showed what Sanchez means with his knockout-of-the-year effort against Jordan Shimmell on May 17 in Minnesota. And he projects to fight as a heavyweight at 6 feet 3 ½ inches.

Next fight: Returns to his home country Dec. 3 to meet two-belt champion Denis Lebedev, who’s trained by Freddie Roach.

4. Gilberto Ramirez; Mexico; super-middleweight; 34-0, 24 KOs;

Nicknamed “Zurdo,” the Carson-trained Ramirez, 25, suffered a torn hand tendon that scrapped his scheduled first WBO super-middleweight title defense in July. He defeated German veteran Arthur Abraham to win the belt in April and he’s shown a willingness to fight Golovkin. Throw in movie-star looks, and his star potential is high.

Next fight: To be determined, as he heals. He has a doctor’s appointment this week and could be placed on a December card.

5. Robert Easter; Akron, Ohio; lightweight; 18-0, 14 KOs;

Won the International Boxing Federation lightweight title Sept. 9 by getting off the canvas to rock Ghana’s then-unbeaten Richard Commey in the 12^th round en route to a split-decision triumph. At 25, he needs to avoid the pitfalls experienced by his friend from the Midwest, Adrien Broner.

Next fight: IBF junior-lightweight champion Jose Pedraza has expressed interest in fighting Easter.

6. Joseph Diaz Jr.; South El Monte; featherweight; 22-0, 13 KOs;

The 23-year-old’s precise punching and impressive movement has lifted the 2012 U.S. Olympian to No. 3 in the WBC ratings and his ninth-round stoppage of Andrew Cancio on the Alvarez undercard last weekend elevates his notoriety.

Next fight: Diaz is in contention to challenge WBC champion Gary Russell Jr. if Diaz’s promoter Oscar De La Hoya and Russell’s manager Al Haymon can work together in spite of active litigation.

7. Felix Verdejo; Puerto Rico; lightweight; 22-0, 15 KOs;

Some boxing savants are not so high on Verdejo’s skills, but the 23-year-old has already made multiple appearances on HBO and it gives him a leg up on other prospects. Also, he was impressive in his last bout in June at Madison Square Garden.

Next fight: Because of an August motorcycle crash, he’s sidelined for the remainder of the year.

8. Erickson Lubin; Orlando, Fla.; super-welterweight; 16-0, 11 KOs;

He is considered neck-and-neck with Spence in internal discussions about who ranks as the best prospect in Al Haymon’s Premier Boxing Champions stable. The 20-year-old southpaw last fought in July, winning every round after scoring knockouts in four of five prior bouts.

Next fight: Uncertain, but may return to the ring in December.

9. Jessie Magdaleno; Las Vegas; super-bantamweight; 23-0, 17 KOs;

The 24-year-old has earned his way for a chance at the top and has the Top Rank machine behind him to ensure strong placement in major fight cards.

Next fight: On Nov. 5, he’ll meet Nonito Donaire for the WBO super-bantamweight title on the Pacquiao-Vargas undercard.

10. Ivan Baranchyk; Russia; super-lightweight; 11-0, 10 KOs;

Nicknamed “The Beast,” Baranchyk isn’t well known yet but promoter Lou DiBella vows the 23-year-old will be a phenom as he follows a deliberate career path. Baranchyk is already a fan favorite at Buffalo Run Casino in Oklahoma, where he’s posted consecutive knockouts.

Next fight: On Friday he returns to the casino to meet Zhimin Wang on Showtime’s “ShoBox” series.

Others to watch: 11. Joseph Parker (20-0, 17 KOs), heavyweight, 24; 12. Frankie Gomez (21-0, 13 KOs), welterweight, 24; 13. Diego De La Hoya (16-0, 9 KOs), super-bantamweight, 22; 14. Joel Diaz Jr. (22-0, 18 KOs), super-lightweight, 24; 15. Jerwin Ancajas (25-1-1, 16 KOs), super-flyweight, 24.

lance.pugmire@latimes.com

Twitter: @latimespugmire