Manny Pacquiao will be at ringside to watch and probably size up his archival Floyd Mayweather Sunday night at the Saitama Super Arena in Japan.

Pacquiao's trip there could lead to something big.

Mayweather is facing Japanese mix-martial arts expert Mikuru Asakura in an exhibition match, the fourth time the unbeaten American fighter will be engaging in an unsanctioned boxing bout.

Last time he fought, Mayweather stopped MMA icon Conor McGregor in August 2017 in Las Vegas.

Pacquiao left Manila yesterday morning accompanied by wife Jinkee and a few associates.

It is expected that with Pacquiao attending the event, they would likely be seeing each other before or after the show.

Like the 45-year-old Mayweather, Pacquiao, who turns 44 in December, is also tinkering with exhibition matches.

In fact, Pacquiao will make his debut in December in Seoul against Korean YouTube personality DK Yoo.

There is also talk that Pacquiao will meet former sparring partner Jaber Zayani, a Frenchman of Tunisian lineage, in February next year in Riyadh.

While Pacquiao is a newbie in this fast-growing endeavour, Mayweather is already a veteran, having racked up a few wins without having to push himself to the limit.

After the McGregor victory, he went to Tokyo and clashed with another MMA fighter in Tenshin Nasukawa.

It was then followed by two more events of the same type, fighting YouTube legend Logan Paul in Florida and ex-sparmate Don Moore in Dubai only last May.

Pacquiao announced his retirement from the sport a month after losing the World Boxing Association welterweight crown to Yordenis Ugas of Cuba in August last year in Las Vegas.

Apart from the welter belt, Pacquiao also won world titles at fly,

super-bantam, feather,

super-feather, lightweight, super-lightweight and super-middle.