Unbeaten super welterweight contender Bakhram Murtazaliev and unbeaten prospects Pablo Rubio Jr. and Amed Medina will compete on the non-televised undercard lineup this Saturday, July 17 from AT&T Center in San Antonio in a Premier Boxing Champions event.

Murtazaliev will compete in an eight-round showdown against Massachusetts’ Khiary Gray, while the Los Angeles-native Rubio Jr. (12-0, 4 KOs) faces Bryan, Texas native Eric Manríquez (7-11-1, 3 KOs) in an eight-round super welterweight duel, plus the 18-year-old featherweight Medina (2-0, 2 KOs) battles South Carolina’s Reginald Hinson (1-0) in a four-round fight.

The non-televised action will also see Rio, Texas-born heavyweight Robert Zavala Jr. (1-0, 1 KO) in a four-round bout against San Antonio’s Levi West and Victoria, Texas-native Xavier Núñez (1-0, 1 KO) stepping into the ring for a four-round attraction.

SHOWTIME CHAMPIONSHIP BOXING begins at 9 p.m. ET/6 p.m. PT and will be headlined by the hard-hitting unified champion Jermell Charlo and the exciting Argentine Brian Castaño going toe-to-toe as all of the super welterweight championship belts are on the line for the first time in the four-belt era.

In the co-main event, Interim WBA Lightweight Champion Rolando “Rolly” Romero will now take on 135-pound contender Anthony Yigit. Yigit replaces Austin Dulay, who was originally scheduled to face Romero, but was forced to withdraw due to injury.

Rounding out the televised attractions, unbeaten middleweight Amilcar Vidal matches up against veteran contender Immanuwel Aleem in a 10-round bout that opens the telecast.