Angel Fierro has been forced to withdraw from Saturday's rematch with Isaac "Pitbull" Cruz, sources told The Ring.

The 140-pound battle of Mexican action fighters was scheduled for the Manny Pacquiao-Mario Barrios PPV undercard in Las Vegas. Cruz (27-3-1, 18 KOs) defeated Fierro in a firefight on February 1 via tight 10-round unanimous decision.

It was a result that begged for a return encounter, but that will now have to wait.

Fierro (23-3-2, 18 KOs) is headed to a hospital for observation after he encountered health issues during his weight cut, sources said.

“I want to start off by apologizing to all the fans that made the trip to Vegas, to Pitbull and his team and everyone involved in the fight,” Fierro’s trainer Robert Garcia wrote on X. “I made the decision this morning to not allow my fighter Angel Fierro to cut any more weight and instructed our team to take him to the hospital. I have a responsibility to not only prepare my fighter to fight, but also to keep him safe. The last few pounds were going to be too dangerous for him to cut and I made the decision to pull him out. Again, we apologize to everyone involved.”

Cruz will remain on the card against replacement opponent Omar Salcido.

Cruz is a former WBA junior welterweight champion. The 27-year-old lost his title via 12-round split decision to now-former titleholder Jose Valenzuela in August.

Fierro, 26, has never challenged for a world title.