While Nick Diaz's MMA future may still be in doubt, the former Strikeforce welterweight champion has decided to return to his Brazilian jiu-jitsu roots.

The World Jiu-Jitsu Expo and Cesar Gracie, Diaz's trainer and manager, have confirmed that Diaz will compete in a BJJ super-fight at the WJJE on May 12 in Long Beach, Calif.

According to Gracie, Diaz wanted to enter one of the WJJE's tournaments, however, Expo officials chose to have him only compete in a super-fight. No opponent has been signed just yet.

Diaz, a black belt under Gracie, hasn't competed in a BJJ match in two years. Gracie said the UFC, "usually doesn't want (Nick) competing (in BJJ) if it's near a fight, (but) he has no fight lined up."

Gracie added that he expects to find out this week when Diaz's hearing with the Nevada State Athletic Commission for his positive drug test following his UFC 143 loss to Carlos Condit will take place. He teased last week via Twitter that Diaz's MMA days aren't over, despite retiring following the loss to Condit.

The first-ever World Jiu-Jitsu Expo will take place at the Long Beach Convention Center. In addition to the Diaz super-fight, fans attending the Expo can take part in free seminars with BJJ stars Renzo Gracie, Braulio Estima, Roger Gracie, Robert Drysdale, Rodrigo Comprido and Andre Galvao.