Gibbons on Casimero-Rigondeaux: We're fighting the tougher fight

Manny Pacquiao Promotions president Sean Gibbons believes that John Riel Casimero will find himself in a bigger challenge against Cuban veteran Guillermo Rigondeaux when the two bantamweight champions clash on Aug. 14 at the Dignity Health Sports Park in Carson, California.

WBO bantamweight champion John Riel Casimero (Team Casimero)

This after WBC champion Nonito Donaire withdrew from the fight after the negotiations went into naught due to issues that involved Casimero's camp as well as the Voluntary Anti-Doping Agency (VADA) testings.

"I think we're fighting the tougher fight, we're fighting the guy who beat Donaire," Gibbons told ESPN's Mike Coppinger. "He's only had one bad fight in his life and that was fighting a guy two divisions bigger than him, Vasiliy Lomachenko. Guillermo Rigondeaux ... dude has a lot of life left in him.

"We're taking on a very difficult challenge," added the MP Promotions chief.

Rigondeaux was the initial opponent set against Casimero, who will defend his WBO title as announced last April.

READ: Casimero wants to retire Rigondeaux, says MP Promotions chief

But after Donaire took the WBC belt from Frenchman Nordine Oubaali last May, there was a quick turnaround in the stacked bantamweight division.

An all-Filipino showdown was created but has suddenly gone down the drain a week later after back-to-back disputes from both camps.

READ: Who is next for the 'Filipino Flash'?

After Donaire's withdrawal, ESPN reported that Gibbons had already apologized and admitted that "it got out of control."

"We jump on the sword and say there were some things that shouldn't have been said. That's boxing. We're not in ballet, we're in boxing."

READ: No disrespect meant to Donaire, says Casimero representative

Meanwhile, Casimero, 32, is riding on a six-match win streak with the latest coming from a technical knockout win over Ghanian boxer Duke Micah last September to improve at 30-4 record on top of 21 knockouts.

The 40-year-old regular WBA champion, for his part, last saw action in February last year with a split decision victory over Venezuelan foe Liborio Solis.

Rigondeaux, who holds a 20-1 slate with 13 KOs, beat Donaire in April 2013 to defend his super WBA super bantamweight title and capture its WBO counterpart at that time.