Top-Rank promoter Bob Arum said Manny Pacquiao could have already fought his last boxing match in the United States last December, believing it's very unlikely for the Filipino champ to fight again on American soil.

In an interview with the Los Angeles Times, Arum was candid in saying that Pacquiao is likely finish fighting before the American crowd.

The promoter blamed the harsh 40 percent income tax on foreign athletes as the primary reason behind the Pacman's decision to fight outside the United States, perhaps for the remainder of his career.

"By fighting outside the country, as he's doing in this Rios fight, Manny doesn't have to pay US taxes anymore - at a rate of 40% for a foreign athlete," the Top Rank Inc. CEO told LA Times correspondent Lance Pugmire.

Pacquiao is scheduled to fight former lightweight champion Brandon 'Bam Bam' Rios on November 14 at the Venetian Macao Hotel in Macau China.

Pacman's upcoming bout marks the first time the eight-division champion fights outside the United State since pummeling Mexico's Oscar Rios to a 12-round unanimous decision victory in 2006.

Top-Rank hopes the Pacquiao-Rios clash will open the floodgates of opportunities in China as they'll attempt to tap the country's 1.34 billion population.

"If this pay-per-view and other things take off like we think they may, I can't imagine Pacquiao will ever again fight in the US," Arum told the LA Times.

According to initial reports, Top-rank is planning to sell their pay-per-view to the Chinese market at cheap price of $5. The fight will also be aired on US pay-per-view, allowing the promotions to cover two big markets at the same time.

"We could do as many as $10 million to $20 million in sales with this. It changes everything. Will it work? We'll see in November," the Promoter added.