Former two-division titlist Timothy Bradley Jr. (31-1-1, 12 KOs) and junior welterweight titleholder Jessie Vargas (26-0, 9 KOs) will fight for a vacant welterweight title -- the one Floyd Mayweather did not accept after beating Manny Pacquiao on May 2 -- on June 27 (HBO) at the StubHub Center in Carson, California, with the next opponent already set for the winner.

The WBO said the winner of Bradley-Vargas will have to make his first defense against mandatory challenger Sadam Ali, a 2008 U.S. Olympian from Brooklyn, New York.

Ali (22-0, 13 KOs) has looked sharp as he has stepped up the level of his opposition in his past two fights on HBO as he knocked out hard-punching contender Luis Carlos Abregu in the ninth round in November and then convincingly outpointed Francisco Santana in a good scrap on April 25 on the Wladimir Klitschko-Bryant Jennings undercard at New York’s Madison Square Garden.