"We're about to make history," Crawford told fans at T-Mobile Arena, where the two will battle to become the first undisputed welterweight champion of boxing's four-belt era.

"When I become undisputed in two world-class weight divisions," it's going to be great," added Crawford, the World Boxing Organization champion who weighed in at 146.75 pounds (66.56 kg).

Spence, the World Boxing Council, World Boxing Association and International Boxing Federation champion, weighed in on the limit of 147 pounds.

Spence, who brings a record of 28-0 with 22 knockouts to the bout, promised a "big show" - a day after he vowed to break Crawford down and "break his will."

Crawford, who owns a record of 39-0 with 30 knockouts, is a former lightweight and undisputed light welterweight world champion who has won all seven of his fights at welterweight by knockout.

He's insisted in the build-up to the fight that his ring legacy is secure, but Spence had made no secret of the fact that beating Crawford - and securing the undisputed crown - would be a validation.

"I feel like if I didn't fight him, his name would always leave a stain on just my name, and if he didn't fight me, my name would always leave a stain on his name, no matter if he wanted to say it or not," Spence said this month.

Spence will get his chance on Saturday - after coming back first from extensive injuries suffered in a 2019 car crash and again from a detached retina that scuppered a planned bout with Manny Pacquiao.

Crawford said Spence has it all to prove.

"They say he’s the big bad wolf, but come fight night we're going to find out if he's all that he says he is," Crawford said. "He's going to have to show me."

bb/sev