By Keith Idec

ARLINGTON, Texas – Errol Spence Jr. just doesn’t believe it.

No matter what Robert Garcia says about his younger brother’s punching power, Spence is convinced that the the smaller four-division champion cannot knock him out in their welterweight title fight Saturday night.

“I don’t believe anybody has the power to knock me out,” Spence said during a press conference Wednesday at AT&T Stadium. “That’s not how I think, that’s not how my camp thinks. So, I mean, that’s out the window, if he thinks he’s gonna get a knockout. But I hope he try, though.”

Spence understandably is considered the superior puncher entering his fight against Garcia.

The taller, stronger southpaw has knocked out 88 percent of his 24 professional opponents. The defending IBF welterweight champion also figures to out-weigh Garcia by approximately 15 pounds once the bell rings to start their 12-round, 147-pound championship match at AT&T Stadium, home of the Cowboys.

The 5-feet-6 Garcia’s disadvantages in height and weight, combined with the 5-feet-10 Spence’s sturdy chin, indicate that Garcia’s probable path to victory is out-boxing Spence over the course of a fight that goes the distance. Robert Garcia, Mikey’s older brother and head trainer, still warned anyone underestimating Mikey Garcia’s power to think twice.

“Well, not only have all of our sparring partners told us, but you know, all of Mikey’s opponents, they’ve said the same thing,” Robert Garcia said. “You know, that until they’re in the ring, they [don’t] realize how strong and how hard Mikey hits. And that’s one thing that Errol Spence doesn’t know. And he’ll find out this Saturday.”

Garcia, a four-division champion, tested his strength by working with considerably heavier sparring partners during his recently completed training camp in Riverside, California. He impacted those sparring partners with his power punches at times, which also has been a common admission among his opponents in official fights.

The unbeaten Garcia has 30 knockouts in 39 fights. In one of his two fights at 140 pounds, he was able to knock down Kazakhstan’s Sergey Lipinets in the seventh round on his way to beating Lipinets by unanimous decision for the IBF junior welterweight title a year ago in San Antonio.

The 31-year-old Garcia will make his 147-pound debut by boxing Spence in a FOX Pay-Per-View main event. Each of his past three fights – junior welterweight victories over Lipinets and Adrien Broner and a lightweight win against Robert Easter Jr. – have last all 12 rounds.

The 29-year-old Spence (24-0, 21 KOs), of nearby DeSoto, Texas, has won 11 straight bouts by knockout or technical knockout.

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