By Miguel Rivera

Top Rank's CEO Bob Arum still believes Floyd Mayweather Jr. vs. Manny Pacquiao is the big reason for boxing's decline in the pay-per-view market.

Mayweather-Pacquiao was the most financially successful event in boxing history. It generated over 4.6 million pay-per-view purchases - demolishing the previous record of 2.4 million held by Mayweather's fight with Oscar De La Hoya in 2007.

But there was a severe backlash after the the fight was over.

Fans were angered over several items. There was little to no fireworks in the fight - and the heavy price tag of $100 for many, made a lot of fans back away from purchasing future boxing pay-per-views. After six years of hype, the fight left most viewers with a very sour taste.

Then there was an immediate scandal when Pacquiao revealed that entered the fight with a right shoulder injury that was further aggravated during the fourth round. Then there was a second scandal over Mayweather using an IV to rehydrate after the weigh-in.

Ever since that fight, not a single boxing pay-per-view has been able to crack a million buys. The closest, at around 900,000 purchases, was last November's fight between Saul 'Canelo' Alvarez and Miguel Cotto. Other PPVs have barely been able to reach 500,000.

Pacquiao returns to pay-per-view this Saturday against WBO welterweight champion Jessie Vargas at the Thomas & Mack Center in Las Vegas. Very few expect that PPV to come close to 500,000 purchases.

"We all know that people were disappointed by the pay-per-view with Manny Pacquiao and Floyd Mayweather, so it's hard to say what we can achieve this weekend, but either way we expect good numbers for this event. Manny Pacquiao continues being one of the great attractions of the sport and we have a pretty good undercard," said Arum to ESPN Deportes.

"If things go as we expect, this card will be seen in China by about 80 or 100 million fans, which is something great and it's the reason why the big sponsors came to this card. "[Zou] Shiming is a major attraction there, and even in Hong Kong the fight will be on pay-per-view."