Pacquiao's financial adviser Michael Koncz told The Associated Press on Thursday that a 45,000-seat boxing arena being built in Las Vegas won't be finished before the end of May and staging the Pacquiao-Mayweather fight in a smaller venue is "foolish from an economic standpoint."
Mayweather challenged and taunted Pacquiao to a May 5 bout in a tweet on Tuesday.
"Manny Pacquiao I'm calling you out let's fight May 5th and give the world what they want to see," he tweeted.
Mayweather is available for a fight in May at the MGM Grand Garden after a judge agreed last week to postpone his jail sentence for domestic violence until June. Mayweather was sentenced to 87 days in jail, but likely will serve less time.
The MGM Grand seats about 17,000, which could fetch around US$20 million in sales, but the larger arena could raise an additional $30 million, Koncz said.
"Why would I tell Manny to fight on the fifth and throw away a percentage of 30 million? That's crazy," he said.
Top Rank promoter Bob Arum has told the Philippines' GMA television the only reason the fight won't happen is if there is an "economic problem."
He said the fight "could happen very, very easily" at the end of May — enough time to build the outdoor arena "the fight so badly needs."
"I will also guarantee Manny's purse," he said. "In other words, Manny doesn't want to go into the ring and just fight out a percentage."
He said Mayweather is looking for "outside parties to guarantee his end of the purse."
"So, until he finds the angel, there is no fight," Arum said.
In a separate interview with GMA, Pacquiao said that if Mayweather agrees to a "50-50 sharing, there will be no problem."
"The purse is not the issue right now, the date is," Koncz said. "But we don't have a problem splitting it 50-50."