IBF welterweight world champion Errol Spence is not underestimating the abilities of his upcoming opponent, undefeated four-division champion Mikey Garcia.

The two unbeaten champions will headline a Premier Boxing Champions on FOX Sports Pay-Per-View event on Saturday, March 16 from AT&T Stadium.

Garcia, who holds the WBC title at 135-pounds, is moving up by two weight division and twelve pounds to take the fight.

In the pre-fight build to the fight, the two boxers have gone face to face on several occasions.

There is a noticeable size difference between the two combatants.

Spence is considered to be a big welterweight and could be headed to the junior middleweight division in the not too distant future.

Garcia feels very confident, after studying footage, that he can upset the very wide odds in Spence's favor.

The contest is by far the biggest opportunity for both - in terms of profile. And the first pay-per-view headliner for both.

Garcia, being the underdog and coming up in weight, has far more to gain in victory.

But Spence plans to put on a boxing clinic.

"Every time I see Mikey I get excited and anxious and want to go to the gym and spar. On Sunday, I sparred 18 rounds because of the whole press conference and face off on Saturday. Looking into Mikey's eyes, I can see how hungry he is and that's motivating me," Spence said.

"Mikey is very difficult because of how he places his punches. He's always thinking and he has a high ring IQ. But I've been clicking on all cylinders. I'm strong mentally and physically and prepared for anything he brings to the table. A win here can definitely catapult me and I'm ready to make it happen.

"I'm 100 percent prepared and focused on Mikey Garcia. I'm hungry and I'm already on weight. I can't wait to put on another show."