John Riel Casimero will have to get through “The Jackal” to remain in position to fight “The Monster.”

Premier Boxing Champions and Showtime announced Thursday that Casimero will square off against Guillermo Rigondeaux in a bantamweight championship fight August 14. The Rigondeaux-Casimero clash, one of seven title fights PBC and Showtime revealed Thursday, will be the main event of a “Showtime Championship Boxing” broadcast from a venue to be determined.

The Philippines’ Casimero, 32, and Cuba’s Rigondeaux, 40, will fight for Casimero’s WBO 118-pound championship and Rigondeaux’s secondary WBA belt.

Casimero calls out Japanese star Naoya Inoue every chance he gets, but their fight has not been rescheduled. They were supposed to meet last April 25 at Mandalay Bay Events Center in Las Vegas, but that card was canceled due to the COVID-19 pandemic.

Inoue (20-0, 17 KOs) is expected to make a mandatory defense of his IBF bantamweight title against another Filipino fighter, Michael Dasmarinas (30-2-1, 20 KOs), on June 19, probably in Las Vegas. The 28-year-old Inoue is recognized as the WBA’s legitimate champion in the 118-pound division as well.

Inoue is the WBA’s “super” champion, whereas Rigondeaux is that sanctioning organization’s “world” champion.

In Rigondeaux, the hard-hitting Casimero will encounter a highly skilled but aged champion who has lost only to three-division champion Vasiliy Lomachenko.

The left-handed Rigondeaux (20-1, 13 KOs, 1 NC) will end an 18-month layoff when he encounters Casimero (30-4, 21 KOs). Rigondeaux out-pointed Panama’s Liborio Solis (30-6-1, 14 KOs, 1 NC) by split decision in his most recent appearance, a 12-round title fight in February 2020 at PPL Center in Allentown, Pennsylvania.

Casimero dominated Duke Micah in his most recent bout.

He dropped Ghana’s Micah (24-1, 19 KOs) in the second round on his way to a third-round technical knockout September 26 at Mohegan Sun Arena in Uncasville, Connecticut. His victory over Micah marked Casimero’s first defense of the WBO bantamweight title he won by stopping South Africa’s Zolani Tete (28-4, 21 KOs) in the third round of their November 2019 bout in Birmingham, England.

Casimero, a three-division champion, has won six straight bouts by knockout since fellow Filipino Jonas Sultan (16-5, 10 KOs) defeated him by unanimous decision in their 12-rounder in September 2017 in Cebu City, Philippines.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.