Chael Sonnen returns for a grappling super fight in August

Chael Sonnen may be done with mixed martial arts after retiring from active competition last week, but that doesn't mean the bad guy is going away.

Just days after Sonnen announced he will be retiring from the UFC, the former light heavyweight and middleweight title contender has signed on to compete in the main event of the upcoming Metamoris 4 card on August 9 in Los Angeles. The news of the match was first reported on Twitter on Thursday.

Metamoris is a Brazilian Jiu-Jitsu promotion that puts on submission only matches with several notable names appearing on past cards including UFC heavyweight Brendan Schaub, Shinya Aoki and a who's who list of grappling legends such as Eddie Bravo and Kron Gracie.

This time around it will be Sonnen headlining the show against Andre Galvao in the main event special attraction.

For those unfamiliar with Galvao -- he is a former Strikeforce fighter who holds a 5-2 record in his MMA career, but is best known for his long list of accomplishments in the grappling world.  Galvao is a two-time world champion as well as an ADCC (Abu Dhabi Combat Club) champion multiple times over including a championship in the absolute weight division.

In other words it's a tall order ahead of Sonnen in this match.

That said, Sonnen has worked a ton on his grappling in recent years to go along with his decades of wrestling experience. Sonnen trains under Brazilian Jiu-Jitsu legend and fellow UFC veteran Vinny Magalhaes, so he will certainly have the right kind of coaching to get ready for a showdown with Galvao.

Metamoris 4 is expected to take place on August 9 from Los Angeles with viewing details still to be announced.