Pablo Cano replaces Lucas Matthysse as Erik Morales' opponent Sept. 17
The bout will be the primary undercard fight before the WBC welterweight title fight pitting Ventura's Victor Ortiz against unbeaten Floyd Mayweather Jr.
Morales-Cano will be for the WBC junior-welterweight title.
The 21-year-old Cano (22-0, 17 KOs) is the highest available ranked boxer to challenge Morales, said Richard Schaefer, Golden Boy's chief executive.
"He's an all-action fighter, and with Marco Antonio Barrera's former trainer Rudy Perez training (Cano), it's another Mexico City-Tijuana battle for Morales," Schaefer said.
Matthysse, from Argentina, withdrew from the bout earlier this week with a viral infection that Schaefer said required hospitalization.
Cano fought last month on a Mexican television card.
Photo: Erik Morales during a fight promotion in August. Credit: Lucy Nicholson / Reuters