Chael Sonnen may have retired from MMA, but that doesn’t mean he won’t compete again.

The former UFC middleweight and light heavyweight title contender has agreed to enter the Metamoris 4 mat in a no-gi match against two-time jiu-jitsu world champion and ADCC winner Andre Galvao, sources told MMAFighting.com. BJEE.com reported the news earlier this week.

Metamoris 4 takes place in Los Angeles on Aug. 9.

A decorated wrestler, Sonnen earned five of his 28 professional MMA victories via submission, notably against Mauricio Rua and Brian Stann. Galvao returned to grappling after a 5-2 run in MMA and won the ADCC 2011 weight and absolute divisions, defeating the likes of Rousimar Palhares and Gunnar Nelson. He became the ADCC 2013 superfight winner with a submission over Braulio Estima.

Vinny Magalhaes and Keenan Cornelius, expected to clash at the third edition of the event, will finally meet on Aug. 9, sources confirmed to MMAFighting.com. Magalhaes, a former UFC light heavyweight and multiple time jiu-jitsu champion, was forced out of Metamoris 3 hours before the no-gi match due to a staph infection. Kevin Casey replaced Magalhaes and lost to Cornelius via heel hook.

MMAFighting.com reported on Friday that Josh Barnett vs. Dean Lister is also set for Metamoris 4.