By Edward Chaykovsky

Top Rank's CEO Bob Arum realizes that tough road ahead in promoting the HBO Pay-Per-View trilogy bout between Manny Pacquiao and Timothy Bradley.

The first fight, in 2012, generated 890,000 pay-per-view buys. Bradley won that bout with a controversial twelve round split decision. The 2014 rematch generated a lower buyrate which came in around 800,000. The rematch was won by Pacquiao with a twelve round unanimous decision.

The trilogy fight takes place at the MGM Grand in Las Vegas. Their prior bouts took place at the same venue.

When Arum spoke to HBO and the pay-per-view distributors, they felt Bradley would be a bigger sell on pay-per-view than the other two candidates, Amir Khan and Terence Crawford.

The selling point of the PPV will be Bradley's "new form" with trainer Teddy Atlas. Bradley fired career trainer Joel Diaz in September and hired Atlas. Their first fight took place in November with Bradley knocking out Brandon Rios.

Arum feels the pay-per-view will be affected by backlash from fans who felt they were snubbed with the lackluster bout between Pacquiao and Floyd Mayweather Jr. on May 2nd in Las Vegas.

"Of course, I understand the reaction to the Mayweather-Pacquiao fight is going to impact us. Clearly, yes. There is no question about that," Arum explained to Yahoo Sports.

"Will we do the same numbers for the first two Bradley fights? Probably not. We're going to try to come as close as we can, and hopefully exceed it, but I understand what we're up against. I've run my numbers and I have done my math. I'm not out here with my head up my ass."