The 26-year-old southpaw felt the battle of making 108 pounds cost him.

"My assessment is that I pushed my body to the limit to make weight," said Mendoza (27-1, 23 KOs). "It was a very important lesson for me."

It looked like the Mexican had a long way to go to work himself back into the world title picture. However, one man's misfortune is another's gain. When Oscar Collazo injured a rib, a shot at WBA and WBC flyweight titlist Sandoval opened up.

Mendoza, who had his first fight since losing to Simsri scheduled for October 3, was only too happy to step into the breach and face the defending champion Saturday on DAZN at Wintrust Arena, Chicago.

"I know he's a tough opponent who throws a lot of punches. He's a world champion for a reason," he said. "He's a fast opponent who handles close-range fighting well. I'll fight my own fight by using my reach to my advantage, looking for counterpunches and hitting hard. I've trained not just physically but mentally as well. I'm going to put on a fight no one expects."

While the loss to Simsri was damaging, Mendoza is unfazed.

"A loss doesn't define me," he said. "What people are overlooking are my 27 previous fights and the way I won them."

He understands that receiving another title shot just six months after his defeat is being met with questions about whether he deserves it.

"There will certainly be people who think that, and it's my responsibility to show what I'm made of," he said. "I'm a fighter, I'm a disciplined person, and I know that respect from the public is earned in the ring."