Khalil Coe couldn’t understand why he felt worn down as he trained for his fight with Manuel Gallegos in November.

His physical condition concerned him to the point that Coe drove himself to a hospital in Philadelphia, Pennsylvania, to get checked out. The Jersey City, New Jersey, native was diagnosed with a kidney infection approximately three weeks before he was set to square off against Gallegos.

Coe didn’t tell his manager, Keith Connolly, or his promoter, Eddie Hearn, that he was hospitalized overnight. Two weeks later, barely a week prior to his fight, Coe was hospitalized again.

Doctors diagnosed him with rhabdomyolysis — the same rare, complex muscle affliction that temporarily derailed the career of Vergil Ortiz from 2022-23. A stubborn Coe kept his medical information private again and moved forward with a 10-round fight on the Jaron Ennis-Karen Chukhadzhian undercard at Wells Fargo Center in Philadelphia.

Coe came in at 175 pounds, the contracted weight limit, on Nov. 8. In hindsight, the light heavyweight contender knows he still should’ve withdrawn from that fight, and not just because Gallegos dropped him four times and upset him by ninth-round technical knockout.

“There was a problem with me making weight,” Coe told The Ring. “I got into the habit of just overtraining and overtraining. I killed my body. I didn’t even know about [rhabdomyolysis] until afterward, when people started telling me about it. ... I honestly shouldn’t have took the fight, but dealing with my pride and things like that, I did it anyway.”

Coe, 28, has had no such issues while training for his immediate rematch with the rugged Gallegos (21-2-1, 18 KOs) on Friday night. Losing to Mexico’s Gallegos taught Coe (9-1-1, 7 KOs) to completely change the way he went about preparing for a main event DAZN will stream from Domo Alcalde in Guadalajara, Mexico (9 p.m. ET; 2 a.m. GMT).

“I’m just learning my body, learning that rest is necessary,” Coe said. “It’s a big part of recovery and it’s needed in this sport. I started training way ahead of time. So, when I got the date I was already in motion and I was already losing weight. I didn’t have that much to lose. And I was taking my rest days and taking recovery more serious, massages, rest, and even just more sleep, getting the right nutrients in the body and things like that. You’ve just gotta make sure you’re on top of it.”

Losing for the first time since he was a decorated amateur made Coe realize he would never reach the top of the light heavyweight division if he didn’t alter his habits.

A more careful Coe hasn’t had any flareups of rhabdomyolysis during this training camp. He feels stronger physically and mentally, which makes Coe confident he will avenge his loss against the hard-hitting Gallegos.

“My physical feels good, but it was more so my mental [outlook],” Coe said. “In the first fight, I knew I was hospitalized and that was always sitting in the back of my head. In my sparring and my training, I haven’t had any mishaps or anything. And I just feel strong. I’m excited. I’m excited to go back and try it again.”

Coe looked sharp at the start of his fight with Gallegos, who buzzed him with a right uppercut in the fourth round. A left hook to the body by Gallegos knocked Coe to one knee with about 1:45 to go in the fifth round.

Coe got up by the time referee Eric Dali counted to eight. He fought ferociously once he reached his feet to avoid getting knocked out.

Gallegos’ right uppercut to Coe’s chin sent him down again with just less than 50 seconds left in the seventh. A right to the body by Gallegos forced Coe to one knee again approximately 30 seconds into the eighth.

An aggressive Gallegos landed a left hook to Coe’s head that knocked him down again only seven seconds into the ninth. Dali immediately waved an end to their bout on the fourth knockdown.

“He had trouble with me like that,” Coe said of his compromised physical condition entering the bout. “So, just imagine me when I’m a hundred percent. He’s gonna see. The world is gonna see. I’ve been seeing a lotta doubt on social media. Even the fact that we came here [to Mexico] for the rematch … I have a statement to make.”

Coe’s first professional defeat didn’t prevent DraftKings from making him a slight favorite to win their rematch. Gallegos, 27, stopped Coe in his first fight after top super middleweight contender Diego Pacheco (23-0, 18 KOs) beat him by fourth-round technical knockout, which took place in July 2023 in Monterrey, Mexico.

“I’m not gonna take any credit from Gallegos,” Coe said. “He definitely a tough opponent. But me beating him is just gonna show I’m on a different [level].”