By Ryan Burton

LAS VEGAS, Nev. - The fighters who will appear on the stacked, action-packed "HIGH STAKES: Mayweather vs. Berto" undercard this Saturday, September 12 live on SHOWTIME PPV(8 p.m. ET/5 p.m. PT) from the MGM Grand Garden Arena took part in their final press conference Thursday at MGM Grand.

In the three pay-per-view fights preceding Saturday's main event between Floyd "Money" Mayweather (48-0, 26 KOs) and Andre Berto (30-3, 23 KOs), Roman "Rocky" Martinez (29-2-2, 17 KOs) will defend his WBO Junior Lightweight Title in a rematch against four-time world champion Orlando "Siri" Salido (42-13-2, 29 KOs), Badou Jack "The Ripper" (19-1-1, 12 KOs) will make the first defense of his WBC Super Middleweight World Title against mandatory challenger "Saint" George Groves (21-2, 16 KOs) and former three-time world champion and Mexican power-puncher Jhonny Gonzalez (58-9, 49 KOs) will be opposed by Puerto Rico's Jonathan "Polvo" Oquendo (25-4, 16 KOs) in a 10-round 130-pound match.

Former IBF World Champion Ishe "Sugar Shay" Smith (27-7, 12 KOs) and longtime top-10 contender Vanes Martirosyan (35-2-1, 21 KOs), who will clash in a scheduled 10-round junior middleweight fight during "COUNTDOWN LIVE: Mayweather vs. Berto" telecast live on SHOWTIME® (6:30 p.m./3:30 p.m. PT), were also in attendance.

Tickets for the live event, which is promoted by Mayweather Promotions LLC. are priced at $1,500, $1,000, $750, $500, $300 and $150 and are on sale now. Tickets are limited to eight (8) per household for all ticket prices except the $150 ticket category, which is limited to four (4) per household. To charge by phone or with a major credit card, call Ticketmaster at (800) 745-3000. Tickets also are available for purchase at or .