Chael Sonnen says he's facing Josh Barnett in Metamoris

Chael Sonnen, who debuts this Friday night as an announcer for the World Series of Fighting, announced on Monday that he would be facing Josh Barnett in a Metamoris submission grappling match later this year.

Barnett, who faces Roy Nelson in the main event of UFC's next live event, a Sept. 26 event on FS 1 from Saitama, Japan (which takes place on Sept. 27 Japan time), is the unofficial heavyweight king of Metamoris, a promotion run by Ralek Gracie. Barnett has grappled twice for the promotion, with submission wins over high-level Brazilian Jiu Jitsu black belts Dean Lister and Ryron Gracie.

Sonnen is coming off a draw with Renato "Babalu" Sobral on May 9 in a Metamoris event.

"I have a match coming up at the very end of October, might even be Nov. 1, I have to look," Sonnen said in an interview on the Australia-based Submission Radio show  "His name is Josh Barnett."

In the battle between two men who are noted for their ability to build fights, Sonnen drew first blood.

"I'll even give you gentleman a prediction... Sonnen wins.  I'm going to take his fat ass down and he will never get up. And let him know I said that."

Barnett would be the heavy favorite, being both significantly bigger, and far more adept at submissions. Metamoris matches have no judging system so if the bout goes the time limit without a submission, it would be ruled a draw.

"I'm going to take Josh down and then I'm going to whisper in his ear, `Welcome to the next 20 minutes of your life.'"

While Sonnen had done analysis work for FOX and ESPN on MMA, and commentated on a pay-per-view event, Friday's WSOF show would be his first play-by-play announcing gig on a nationally televised show.

The WSOF show features a rematch with lightweight champion Justin Gaethje (14-0) against Luis Palomino (23-10), from the Comerica Theater in Phoenix. Their first meeting, on March 28, in the same building, which Gaethje won via late third-round stoppage, was one of 2015's best MMA fights.