Julio Cesar Chavez Jr. on weight as weigh-in looms, assistant manager says

Julio Cesar Chavez Jr. jabbed his way through a shadow-boxing session early Friday morning, stepped on a personal scale and saw the number he needed: 164.5 pounds.

As Friday’s official weigh-in at 3 p.m. awaits, Chavez (50-2-1, 32 knockouts) is said to believe his commitment to reach the negotiated catch-weight limit for his Saturday HBO pay-per-view bout against Mexican countryman Canelo Alvarez (48-1-1, 34 KOs) foretells similar success in the T-Mobile Arena ring.

Chavez assistant manager Sean Gibbons said the fighter took no extreme short cuts to reaching the weight, like employing a sauna.

“It’s good for people to know he did it right, that, ‘You’re going to get your money’s worth,’ ” Gibbons said.

Chavez hasn’t weighed as low as 164.5 pounds since his 2012 middleweight-title unification loss to Sergio Martinez.

His uninspired devotion to the sport showed during subsequent weigh-in struggles and last-minute deal re-negotiations heaped doubt on his ability to make the weight for Alvarez, who fought in September for a 154-pound world title.

If Chavez weighs anything above the catch-weight 164.5-pound limit later Friday, he’ll owe a $1 million penalty from his $3 million guaranteed purse.

Alvarez has a $5 million guarantee. Alvarez, with a victory, would move toward a September showdown against unbeaten three-belt middleweight champion Gennady Golovkin in September, said his promoter, Eric Gomez.

But Chavez’s seriousness even as he remains a 6-1 underdog is a point driving interest in the Cinco de Mayo weekend bout.

Chavez could rehydrate up to possibly 190 pounds by Saturday night, saying he’ll seek to use the advantage to bully Alvarez while sending heavy punches his rival’s way.

“He’s getting it out there: ‘I’m for real,’” Gibbons said. “At no point did he ever have stress making the weight, nor did he put his body through any physical duress.

“For the fans of Julio, he dedicated himself to making the weight correctly. He put in the time. He put in the work. Because he wants to give his fans a victory Saturday night.”

lance.pugmire@latimes.com

Twitter: @latimespugmire