Miguel Berchelt realized very early in his ill-fated fight with Oscar Valdez that the biggest bout of his career simply would not go his way.

The former WBC super featherweight champion claims that the lingering effects from COVID-19, which caused a two-month postponement of their 130-pound title bout, cost him dearly versus Valdez. Berchelt’s poor performance included suffering three knockdowns, one apiece in the fourth, ninth and 10th rounds.

Valdez viciously finished off a battered Berchelt when he stepped back and blasted his Mexican rival with a left hook that sent Berchelt crashing to the canvas, face first.

“The first thing that I learned from that fight is not to fight if I’m sick,” Berchelt told BoxingScene.com. “I felt I was ready in my heart and my mind, but for some reason, my body didn’t respond at all. It was like the secondary effects from the COVID.”

Those closest to Berchelt advised him not to fight during the buildup toward his rescheduled clash versus Valdez. Berchelt didn’t want to postpone their ESPN main event again, so he went forward with their fight in February 2020 at MGM Grand Conference Center in Las Vegas.

“Everyone around me, even my girlfriend, told me not to fight,” Berchelt said. “I wasn’t fully sick. My COVID happened in November, but once the fight started, I didn’t feel like myself. And even when I saw the fight again, I didn’t feel like myself.”

Thirteen months later, Berchelt finally will return to the ring. He is scheduled to meet Namibia’s Jeremiah Nakathila in another main event ESPN will air from Resorts World Las Vegas on Saturday night (10 p.m. ET; 7 p.m. PT).

Nakathila, 32, is most known for his lopsided loss to Shakur Stevenson in their 12-round, 130-pound WBO interim title fight last June 12 at Virgin Hotels Las Vegas. The hard-hitting Nakathila (22-2, 18 KOs) seemed to affect Stevenson with a right hand late in the sixth round, but otherwise a defensively driven Stevenson completely out-boxed Nakathila in a forgettable fight throughout which Nakathila contends Stevenson was “scared” to engage with him.

“I saw some footage of Nakathila, but not much,” said Berchelt, who Caesars Sportsbook has made almost a 6-1 favorite. “It was mostly the Shakur fight. I thought that he looked just OK in that fight. There isn’t much film on him because he mostly fights in Africa. But I am not taking the Nakathila that fought Shakur as the Nakathila that’s gonna face me. I’m just coming to put on a great performance and send a message to the lightweight division, that I’m here to become world champion once again.”

Berchelt, 30, has boxed at, near or above the lightweight limit three times during a pro career that began in November 2010. The contract weight for his fight with Nakathila is the maximum for the lightweight division, 135 pounds.

“I’m just ready to go,” Berchelt said. “For this fight, I really want to show that I’m here to stay. A couple of things happened in the last fight. Four years of making the weight, 130, was getting tougher for me. So, my body was already asking for the change. And on top of that, the secondary effects of COVID were a problem. But in this fight, I want to show I’m here to stay and the fighters in the 135-pound division, they’re gonna have to deal with me.”

Making the 130-pound limit became problematic toward the end of Berchelt’s four-year championship reign. He remained in that division, however, because better opportunities existed within it for him.

“I wanted to stay as champion, even though my body was already asking me for the change,” Berchelt said. “Once you have so many title defenses [six], the purses go up and with every title defense I made, I kept getting more money and more money. So, that’s why I kept making the sacrifices to make 130, even though I felt like it was time for me to move up.”

Windhoek’s Nakathila also has moved up from the 130-pound division to 135 for this fight.

Valdez, meanwhile, has advanced to a 130-pound title unification fight against Stevenson. Nogales’ Valdez (30-0, 23 KOs) and Stevenson (17-0, 9 KOs), a southpaw from Newark, New Jersey, are scheduled to meet in a main event ESPN will air April 30 from MGM Grand Garden Arena in Las Vegas.

While his devastating defeat to Valdez still stings, Berchelt is focused on making another championship run within the lightweight division.

“We lost a battle, but we haven’t lost the war,” Berchelt said. “I’m just ready for war this Saturday.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.