The roster for next month’s ambitious Quintet Ultra continues to fill, and four new team participants have been booked, along with three “superfight singles” matches.

Featuring a unique 5-on-5 team grappling concept, Quintet Ultra takes place Dec. 12 at Red Rock Casino in Las Vegas and streams live on UFC Fight Pass. While the events often feature big-name mixed martial artists, Quintet Ultra will see teams representing the biggest promotions in MMA history face off with Team UFC, Team Strikeforce, Team WEC and Team PRIDE.

MMA Junkie today learned from Quintet officials that four new fighters have agreed to compete at the event, with current welterweight contender Gilbert Burns joining team UFC, former light heavyweight champion Muhammed Lawal added to Team Strikeforce, 15-year veteran Cub Swanson repping Team WEC and submission ace Gregor Gracie joining Team PRIDE.

Quintet founder, MMA legend Kazushi Sakuraba, said he was thrilled to announce all of the additions, but as a former Gracie hunter was now happy to have a member of MMA’s founding family on his side.

“You can’t have PRIDE without Gracie,” Sakuraba said. “I’m very happy to welcome one of the new generation of Gracie fighters to the team. Gregor has fought in Quintet, and he always goes for the win, so he’s a great addition. Hopefully he’ll make things easier for this old man!”

In addition to the team competition, three singles matches were announced, with some notable names in both the MMA and grappling world, with Craig Jones vs. Fredson Paixao and Pearl Gonzalez vs. Danielle Kelly joining a previously announced matchup of Gordon Ryan vs. Aleksei Oleinik.

More details on participating grapplers and team rosters will be revealed in the weeks to come. The card will stream live at 10 p.m. ET on UFC Fight Pass.

The current Quintet Ultra lineup includes:

TEAM UFC

• Anthony Johnson (captain)
• Sean O’Malley
• Gilbert Burns

TEAM STRIKEFORCE

• Gilbert Melendez
• Jake Shields
• Muhammed Lawal

TEAM WEC

• Chad Mendes (captain)
• Glover Teixeira
• Cub Swanson

TEAM PRIDE

• Kazushi Sakuraba (captain)
• Takanori Gomi
• Gregor Gracie

SUPERFIGHT SINGLES MATCHES

• Craig Jones vs. Fredson Paixao
• Gordon Ryan vs. Aleksei Oleinik
• Pearl Gonzalez vs. Danielle Kelly