Vergil Ortiz Jr., a rising star at 147 pounds, was forced to withdraw from Saturday’s fight against Michael McKinson in Los Angeles after being diagnosed with rhabdomyolysis, Golden Boy Promotions announced Tuesday.

The fighter’s father and trainer, Vergil Ortiz Sr., told ESPN that his son underwent blood tests on Friday at Adventist Health White Memorial in L.A. Ortiz trained Saturday and then rested Sunday. After the results revealed rhabdomyolysis, Ortiz was admitted to the hospital on Monday and released Tuesday evening.

Rhabdomyolysis is a breakdown of muscle tissue that releases the damaging protein myoglobin into the blood, which can lead to kidney damage. Ortiz Sr. said his son was instructed to rest for a few weeks and consume lots of fluids to flush the protein out. The cause of the condition wasn’t clear, but Ortiz Sr. said he noticed something was wrong about two weeks ago.

“He was dropping weight too fast for me,” Ortiz Sr. said. “That’s when I knew something was wrong. … I just know my son so well, he can’t go from 100 miles per hour one day to zero the next [in sparring].

“When my son fights, he fights a certain way. His movements require a certain balance. … He just seemed like he was off balance. He wasn’t himself. I thought maybe he had something on his mind. … He could have almost died with this stuff. His kidney and liver were starting to go down. We caught it at the right time.”

Ortiz Jr. tweeted later Tuesday, expressing his disappointment in having to miss Saturday’s fight.

“Camp was going great, I was doing very good in sparring and training in general. But for the last 2 weeks I didn’t feel like myself,” he wrote in his tweet. “I just felt like my body was deteriorating and I didn’t know why and it was frustrating. Being the fighter that I am, I tried toughing it out, but when it’s your own body fighting against you there’s little you can do.”

Ortiz went on to write, “It could’ve been a lot worse and I’m thankful that we caught it on time. I am very sorry if I let you guys down. Believe me if there was a hair of a chance of me fighting, I would be.”

The fight against McKinson was set to headline a Golden Boy Promotions on DAZN card. McKinson could fight a replacement opponent, but the card is in jeopardy of being canceled, sources told ESPN. It’s also possible the welterweight co-feature pitting Alexis Rocha against Blair Cobbs will be elevated, sources said.

“We wish Vergil a very quick and speedy recovery,” said Ortiz’s promoter, Oscar De La Hoya. “As fighters, our first instinct is to fight whatever we have and tough it out. It takes a lot of courage to admit that something is wrong and get the care that you need. We are confident that we will be seeing Vergil in the ring again very soon.”

Ortiz, 23, has risen to the No. 4 spot in ESPN’s welterweight rankings with a string of impressive knockouts over solid opposition. A power-punching Texan, he scored a seventh-round knockout of former champion Maurice Hooker in March 2021. Ortiz followed with an eighth-round TKO of Egidijus Kavaliauskas in August.

McKinson (21-0, 2 KOs), a 27-year-old from England, was stepping up to the world-class level for the first time. He has only two knockout wins, but he has scored six knockdowns in his past four fights. He has never competed in the U.S.

ESPN Boxing