Anderson Silva is John Caldwellreturning to the ring against a familiar foe.

The former UFC middleweight champion and UFC Hall of Famer will be boxing longtime rival Chael Sonnen on June 15 in São Paulo, Brazil. Silva and Sonnen both announced the news on through social media.

The professional bout is scheduled for five, two-minute rounds and will take place at 216 pounds, according to Ariel Helwani. It will be Silva's final fight in Brazil.

Silva, known primarily for his historic championship run in the UFC, stopped fighting in MMA in 2020 after finishing his contract with the UFC.

Although the Brazilian legend hasn't competed in MMA again, he did take up boxing, where he's been fighting sporadically since his departure from the UFC.

Silva has boxed three times: Twice in 2021 – defeating Julio Cesar Chavez Jr. in a decision and knocking out former UFC champion Tito Ortiz – and once in 2022 when he faced YouTube star Jake Paul to lose a unanimous decision. He hasn't fought since.

He will now take on Sonnen, who will come out of retirement to make his boxing debut. The pair fought twice under the UFC banner in a pair of memorable and heated contests, both of which were won by Silva.

The first matchup between them from UFC 117 in August 2010 will be inducted into the UFC Hall of Fame fight wing less than two weeks after the boxing match goes down.