Four months after he withdrew from a “Showtime Championship Boxing” main event versus John Riel Casimero, Nonito Donaire has been scheduled to fight another fellow Filipino on Showtime.

BoxingScene.com has learned that Donaire will make a mandated defense of his WBC bantamweight championship against unbeaten Reymart Gaballo on December 11. Showtime will televise Donaire-Gaballo as the main event of a tripleheader from Dignity Health Sports Park in Carson, California.

Donaire (41-6, 27 KOs) and Gaballo (24-0, 20 KOs) will fight for the WBC 118-pound crown Donaire won by knocking out previously undefeated French southpaw Nordine Oubaali (17-1, 12 KOs) on May 29 at Dignity Health Sports Park. Showtime also aired the Donaire-Oubaali bout.

Donaire, who will turn 39 on November 16, agreed to make a quick turnaround for a title unification fight with Casimero (31-4, 21 KOs), the WBO bantamweight champion, on August 14 at Dignity Health Sports Park. Donaire pulled out of that fight about a week after agreeing to it because he was dissatisfied with Casimero’s enrollment in the WBC’s “Clean Boxing Program,” which is administered by the Voluntary Anti-Doping Association.

An agitated Donaire also took exception to comments Casimero’s promoter, Sean Gibbons, directed toward his wife/manager, Rachel Donaire, on social media.

Casimero instead defeated Cuban southpaw Guillermo Rigondeaux (20-2, 13 KOs, 1 NC) by split decision in a dreadfully dull, 12-round main event August 14.

Donaire later gave Casimero career advice after Probellum, which promotes Donaire, won the purse bid for the right to put on Casimero’s obligatory title defense against England’s Paul Butler (33-2, 15 KOs). The Casimero-Butler bout will not be part of Showtime’s tripleheader December 11.

The 25-year-old Gaballo, meanwhile, will challenge Donaire because he won the WBC interim bantamweight championship in controversial fashion over Emmanuel Rodriguez last December 19 at Mohegan Sun Arena in Uncasville, Connecticut.

Judge David Sutherland scored their 12-round fight for Puerto Rico’s Rodriguez (19-2, 12 KOs, 1 NC) by a wide distance, 118-110. The other two judges, John McKaie (115-113) and Don Trella (116-112), saw a different fight entirely and scored it for Gaballo, who hasn’t boxed since he edged Rodriguez, a former IBF bantamweight champ.

Rodriguez replaced Oubaali, who battled COVID-19 before eventually facing Donaire, in that “Showtime Championship Boxing” main event 10 months ago. Oubaali was supposed to defend his title against Donaire, but Donaire also contracted COVID-19 and Gaballo substituted for him.

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