By Jake Donovan

Tony Harrison and Willie Nelson have both vowed to steal the show from main event players Keith Thurman and Luis Collazo on Saturday's ESPN-televised card at USF Sun Dome in Tampa, Florida.

Thurman returns to the Tampa region for the first time in nearly six years, as he puts his welterweight belt and unbeaten record on the line versus a former titlist in Collazo. In the televised opener, Harrison and Nelson fight merely for bragging rights.

Both did their share of bragging and barking during Thursday's press conference, behind the mic, in each other's face and from across the room after being physically restrained. The press session lasted all of 30 minutes, but was best remembered for Harrison and Nelson nearly coming to blows.

By his own admission, the afternoon went according to plan for Nelson, who had more motivation than anyone else in the room to get people talking. The Cleveland native has been out of the ring since a 10-round loss to Vanes Martirosyan last October, a setback that ended a six-fight win streak.

Few if anyone give Nelson much of a chance of winning this weekend, perhaps all the more reason to raise a ruckus during the press session and also forcing Harrison out of his element.

"I wanted to get Tony pumped up today and get him off of his game plan so we can capitalize on fight night," Nelson (23-2-1, 13KOs) said afterward. It worked, I even had his team fired up. So I'm extremely confident, it's on to the fight."

It began with words behind the mic, but escalated into more than that after Nelson made a point to get in Harrison's face during the obligatory photo-op staredown. Harrison felt disrespected, shoving Nelson and threatening to make it more than that before the two were separated by promoter Leon Margules.

From there, a war of words ensued—at close range, from across the room and then once again on the dais. Their constant barking overshadowed a peaceful staredown between Thurman and Collazo, both of whom couldn't help but laugh at the antics of their supporting cast.

"Somebody in the arena better bring a pillow," Thurman joked to the assembled media on hand before turning his attention to the fueding middleweights. "It's clear one of y'all are going to sleep!"

Harrison (21-0, 18KOs) vows that it will be his opponent who's put to sleep, and now given additional motivation in addition to the necessary skill set to carry out that goal. The unbeaten prospect on the rise has scored 10 straight knockouts, none lasting more than three rounds.

The actions taken on Thursday were enough to put him in fight mode, more than two full days before the opening bell.

"I felt the pressure he was bringing," Harrison said afterward. "He touched my hat. He got too close and that was enough. Now it's on."

It was enough to bring "the Detroit" out of Harrison, who is no stranger to having to fend for himself. Even after the two were separated and ordered to stand down, Nelson insisted on having his say.

The antics were out of character for the fringe contender from Cleveland, a point Harrison repeatedly raised.

"I see it in your eyes. You weak, you weak"  Harrison said to Nelson at the heat of the verbal exchange. "I see it in your eyes, you scared."

Even afer the two were separated, the trash talk continued. As Harrison was walking away, Nelson felt the need to offer another parting shot.

"Shut the f*** up, punk!" Harrison shouted back at Nelson. "You ain't about that and you know it. You soft-spoken, say soft-spoken. Don't get out your element."

The 10-round middleweight bou—now officially a grudge match—serves as the televised opener for the first installment of Premier Boxing Champions (PBC) on ESPN.

Jake Donovan is the Managing Editor of BoxingScene.com. Twitter: @JakeNDaBox