Manny Pacquiao will follow former foe Floyd Mayweather and appear under the banner of Japan's Rizin Fighting Federation, the organization's president Nobuyuki Sakakibara said Monday.

Sakakibara uploaded a pair of posts to Twitter -- one each in English and Japanese -- to announce the World Boxing Association welterweight champion's participation in the upcoming Rizin promotion in Yokohama on April 21.

"I'm here in the Philippines. RIZIN.15 will have this man involved in a way," Sakakibara tweeted. "We will be ready to announce as I get back to Japan!"

The tweets included a pair of photos showing Sakakibara with Pacquiao. In one of the photos, Pacquiao appears to be signing a contract, although it remains unclear what his involvement in the promotion will be.

Pacquiao last fought on Jan. 19, when he successfully defended his WBA title against Adrien Broner in Las Vegas.

[Getty/Kyodo]

The 40-year-old, considered one of the greatest pound-for-pound boxers of all time, currently serves as a senator in his native Philippines.

Former five-weight-class world champion Mayweather beat Japanese mixed martial artist Tenshin Nasukawa by technical knockout in an exhibition boxing match at Rizin's New Year's Eve promotion near Tokyo.