As previously reported by BoxingScene.com, Top Rank's CEO Bob Arum - who promotes WBO welterweight champion Terence Crawford - lashed out at Al Haymon - the head of Premier Boxing Champions.

Arum claims that Haymon is doing everything possible to prevent a unification between Crawford and IBF welterweight champion Errol Spence.

Crawford, through his deal with Top Rank, is contractually tied to ESPN.

While Spence, through his deal with PBC, is featured on Fox Sports and Showtime.

According to Arum, Spence wants to face Crawford - but the veteran promoter expects Haymon to persuade Spence to fight someone else.

“No, because you can hear what he’s gonna say. "He's gonna say, ‘Spence, listen to me. Don’t listen to the white guys, because if you listen to the white guys they’re gonna steer you down the road. Listen to me, brother. We’re part of a brotherhood. And if I tell you not to fight Crawford, I’m telling you not to fight Crawford.’ That’s exactly what he will say," Arum said in an earlier piece on BoxingScene.

Spence and Haymon hold a significant advantage.

Most of the top welterweights are under contract with PBC - like Manny Pacquiao, WBC champion Shawn Porter, WBA champion Keith Thurman, Danny Garcia, the comebacking Marcos Maidana and several others.

On the other side, Crawford's options are extremely thin.

And Tim Smith, Vice President of Communications for PBC, is not surprised that Arum lashed out at Haymon.

Smith realizes that Arum is under pressure to deliver a big fight for Crawford, and the most likely future opponents are Top Rank promoted boxers like Egis Kavaliauskas and Alexander Besputin - both unknown to most casual fans.

“There are more great fights ahead of Terence Crawford like the one he had against Amir Khan without pulling Errol Spence into the picture, just as there are several great fights against champions [for Spence]," Smith said to The Los Angeles Times.

“We’ll let Arum handle Top Rank and Crawford business while we attend to Errol Spence and Premier Boxing Champions business -- truly exciting times in boxing and the welterweight division.

“The whole thing reeks of desperation [from Arum]. It’s embarrassing, really. These fights happen when the time is right.”