Cristobal Arreola-Seth Mitchell set

A fight between heavyweights Cristobal Arreola and Seth Mitchell that has been in the works for several weeks, and close enough to being signed that both fighters have been training, has been finalized, Golden Boy chief executive Richard Schaefer told ESPN.com on Thursday.

Arreola and Mitchell, two of America's most exciting big men, will meet Sept. 6 (Showtime) at the Fantasy Springs Resort Casino in Indio, Calif., not far from Arreola's hometown of Riverside, Calif.

"We got the fight done. It's all set," Schaefer said. "Arreola and Mitchell, it's a crossroads fight for both guys. They know it's do or die. That's what makes it so interesting."

Schaefer said the winner of the fight could wind up next facing top American prospect Deontay Wilder (28-0, 28 KOs), the 2008 U.S. Olympic bronze medalist who is also in the Golden Boy stable. Wilder first faces former world titleholder Sergei Liakhovich (25-5, 16 KOs) on Friday night, also at Fantasy Springs.

"I could definitely see the winner between Arreola and Mitchell fighting Deontay Wilder next," Schaefer said. "We could come out of this thing with one true American challenger for the heavyweight title next year."

The co-feature will pit former bantamweight and junior featherweight champion Rafael Marquez against Efrain Esquivias (16-2-1, 9 KOs), 30, of Gardena, Calif., in a scheduled 10-round junior featherweight fight.

Marquez (41-8, 37 KOs), 38, younger brother of fellow Mexican star Juan Manuel Marquez, recently agreed to a four-fight deal with Golden Boy and will be fighting for the first time since being stopped in the ninth round by former junior bantamweight champion Cristian Mijares in an October featherweight fight.

Marquez has lost three of his past five fights dating to 2010, but signed with Golden Boy looking for one more title opportunity.

Esquivias is 0-2-1 in his past three, but the losses were by decision to former junior featherweight titlist Rico Ramos and Jhonatan Romero, who went on to win a 122-pound world title.

Mitchell (26-1-1, 19 KOs), 31, of Brandywine, Md., a former Michigan State linebacker, was a fast-rising heavyweight contender before running into Johnathon Banks, who floored him three times and knocked him out in the second round in an upset in November. Mitchell avenged the loss on June 22, winning a unanimous decision in an uncharacteristically dreary fight.

Even with the win, Mitchell was hurt multiple times and left open the question of his ability to take a punch.

The 32-year-old Arreola (35-3, 30 KOs) fought for a world title in 2009 but was stopped in the 10th round by Vitali Klitschko.

Arreola is coming off a unanimous decision loss to Bermane Stiverne in April in a world title eliminator to determine Klitschko's next mandatory challenger. Stiverne knocked Arreola down in the third round and badly broke his nose, which required surgery.

When the fight was first in the works, Dan Goossen, Arreola's promoter, told ESPN.com last month, "It's a great fight for both fighters and I think it's a great fight-fans' fight. They'll both come at each other. Fans really love the heavyweights, especially ones that like to get in there and bang with one another. (Arreola is) breathing well. He's fine. He had a little surgery on (his nose), and a few weeks later he was good to go."