ONE Championship grappling king Kade Ruotolo confirms MMA debut "in near future" ahead of Fight Night 21

Kade Ruotolo is finally set to make his mixed martial arts debut in ONE Championship.

The lightweight submission grappling champion, 21, will compete in a 180-pound catchweight grappling bout against Francisco Lo at ONE Fight Night 21 this weekend in Bangkok.

But the 21-year-old American has already signed up for an MMA bout in the Asia-based martial arts promotion later this summer, Sportskeeda understands.

"At some point this year no matter what, it's happening," Ruotolo told Sportskeeda. "I obviously can't say too much, but in the near future it's going down. I'm beyond eager, I'm beyond excited. I'm shadowboxing in the corner every day, I'm fired up."

Kade Ruotolo set to share upcoming ONE Fight Night card with twin brother Tye

Kade will be joined on Saturday morning's card at Lumpinee Stadium in Bangkok by his twin brother Tye Ruotolo, ONE Championship's welterweight submission grappling champion.

The brothers have conquered all before them so far in ONE, often with alarming ease, but Tye expects his toughest test this weekend when he faces Australia's Izaak Michell.

"He's gonna come to fight," Tye Ruotolo said. "He's very aggressive, decorated and accomplished, so it should be a very tough match. I'm excited."

Tye Ruotolo celebrates becoming ONE welterweight submission grappling champion.

Though his belt will not be on the line, Kade is also anticipating his biggest hurdle to date in ONE. He said:

"Francisco is a big name in the jiu-jitsu community, everyone knows he's a sniper with the subs."

Kade further added:

"He brings a high pace, he has high-level wins over multiple ADCC veterans. Not just wins but finishes. I believe like Tye said, it's probably my toughest matchup I've had in ONE too."

Like his brother Kade, Tye is also anticipating a switch to MMA – but he still has unfinished business in grappling, and hopes to entice Nicholas Meregali and even the legendary Gordan Ryan to face him in ONE.

Kade and Tye Ruotolo with their titles.

As for Saturday, the twins are both prediction submissions – a "d'arce" for Tye, and a "leg lock" for Kade – which would likely earn them another US$50,000 bonus each.