John Riel Casimero would welcome an opportunity to challenge Naoya Inoue in Inoue’s home country of Japan.

The WBO bantamweight champion senses, though, that Inoue doesn’t want to face him in what would be an intriguing 118-pound title unification fight. The Philippines’ Casimero discussed a potential showdown with Inoue following his 12-round, split-decision defeat of reluctant challenger Guillermo Rigondeaux on two weeks ago in Carson, California.

“I always call [out] Naoya Inoue, but now I know he’s scared of me, like Donaire,” Casimero said. “But, you know, if he signed a contract, let’s do it. I fight him. But, you know, Naoya Inoue and Donaire [are] all scared. I don’t know what happened.”

Inoue (21-0, 18 KOs), who owns the IBF and WBA “super” bantamweight titles, and Casimero (31-4, 21 KOs), a champion in three weight classes, were scheduled to fight in April 2020. ESPN was set to televise Inoue-Casimero as a main event from Mandalay Bay Events Center in Las Vegas, but that card was canceled at the onset of the COVID-19 pandemic.

Inoue instead fought Australia’s Jason Moloney (22-2, 18 KOs), whom Inoue knocked out in the seventh round October 31 at MGM Grand Conference Center in Las Vegas. Most recently, Inoue annihilated another Filipino fighter, overmatched mandatory challenger Michael Dasmarinas (30-3, 21 KOs), a third-round knockout victim June 19 at Virgin Hotels Las Vegas.

The 28-year-old Inoue is supposed to return to the ring in his native Japan in December. Speculation persists that he’ll fight Donaire again in what also would be a championship unification bout.

Inoue defeated Donaire (41-6, 27 KOs) by unanimous decision in an entertaining 12-rounder in November 2019 in Saitama, Japan. Donaire has since regained the WBC bantamweight title.

The 38-year-old Donaire agreed in June to replace Rigondeaux (20-2, 13 KOs, 1 NC) as Casimero’s opponent Saturday night. “The Filipino Flash” withdrew from their fight soon thereafter because he and his wife/manager, Rachel Donaire, weren’t convinced Casimero was properly enrolled in the Voluntary Anti-Doping Association’s testing program for performance-enhancing drugs.

Sean Gibbons, the president of Manny Pacquiao’s promotional company, emphasized that the 32-year-old Casimero wouldn’t have any problem traveling to Japan to fight Inoue.

“Let me put it this way – the guy’s been to nine countries, won three world titles in nine different countries,” Gibbons said following a main event Showtime televised from Dignity Health Sports Park. “Japan’s the last one. It’ll be number 10, when he knocks Inoue out. We love Japan. We love the Japanese people, love to fight there. … Give him the address. Give him the address, he’ll come by, no problem. The champ’s a fighter. That’s all I can say. He’ll fight anywhere, anytime, against anybody. He’s the WBO champ.”

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