Naoya Inoue’s Top Rank debut is all but set.

BoxingScene.com has learned that the unbeaten IBF/WBA bantamweight champion is going to box WBO 118-pound champ Johnriel Casimero in a title unification fight April 25 in Las Vegas. Inoue’s first fight with Bob Arum’s Top Rank Inc. likely will be televised live on ESPN, but it’s still possible it’ll be offered on ESPN+, the network’s $5-per-month streaming service.

The bout between Japan’s Inoue (19-0, 16 KOs) and the Philippines’ Casimero (29-4, 20 KOs) could be held at Mandalay Bay Events Center, though the site is not yet set. An official announcement of the Inoue-Casimero match will be made in the coming weeks.

Arum’s company signed the hard-hitting Inoue to a multi-fight agreement after his action-packed, 12-round, unanimous-decision win over former four-division champion Nonito Donaire in the final of the World Boxing Super Series’ bantamweight tournament November 7 in Saitama, Japan. The Inoue-Donaire slugfest was voted “Fight of the Year” by the Boxing Writers Association of America for 2019.

Casimero won the WBO bantamweight championship three weeks later by upsetting Zolani Tete (28-4, 21 KOs) in the third round of their November 30 fight in Birmingham, England. The 30-year-old Casimero, a former IBF flyweight and IBF/WBO light flyweight champion, dropped South Africa’s Tete twice in the third round before their scheduled 12-rounder was stopped by referee Steve Gray.

Fellow Filipino Manny Pacquiao’s company promotes Casimero.

Michael Dasmarinas and Nordine Oubaali also were considered as opponents for Inoue’s next fight.

The Philippines’ Dasmarinas (30-2-1, 20 KOs) is the mandatory challenger for the 26-year-old Inoue’s IBF title, but Inoue was granted an exception so that he can partake in a championship unification fight versus Casimero. Oubaali (17-0, 12 KOs) is headed for a mandatory defense of his WBC bantamweight championship against Donaire (40-6, 26 KOs), the No. 1 challenger for his title.

A purse bid for the Oubaali-Donaire fight is scheduled for Tuesday in the event that their handlers can’t work out a deal before then. The two sides were granted a one-week extension this past Tuesday so that they could continue negotiating.

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