LAS VEGAS – British superstar and former unified super lightweight world champion Amir “King” Khan and former two-division world champion Devon Alexander “The Great” made their ‘Grand Arrivals’ and performed a light workout on Wednesday at MGM Grand, just three days before their welterweight showdown this Saturday, Dec. 13, live on SHOWTIME. Photos by Tom Hogan/Hogan Photos and Esther Lin/SHOWTIME.

Khan (29-3, 19 KOs), of Bolton, England, and Alexander (26-2, 14 KOs), of St. Louis, will square off in the 12-round main event of a SHOWTIME CHAMPIONSHIP BOXING® quadrupleheader from the MGM Grand Garden Arena in Las Vegas.

In the co-feature, power-punching interim WBA Welterweight World Champion Keith “One Time” Thurman (23-0, 21 KOs), of Clearwater, Fla., will defend against consensus top-five ranked contender and fellow unbeaten Leonard Bundu (31-0-2, 11 KOs), of Lazio, Italy, in a 12-round bout.

Former three-division world champion Abner Mares (27-1-1, 14 KOs), of Downey, Calif., will return to the ring against Mexico’s Jose Ramirez (25-4, 15 KOs) in a 10-round featherweight battle and Jermall Charlo (19-0, 15 KOs), of Houston, will take on Lenny Bottai (22-2, 9 KOs), of Livorno, Italy, in a 12-round IBF junior middleweight title eliminator fight.

In matchups on SHOWTIME EXTREME (7 p.m. ET/PT, delayed on the West Coast), undefeated up-and-coming Jermell Charlo (24-0, 11 KOs), of Houston, will meet Mario Lozano (27-5, 20 KOs), of Chihuahua, Mexico in a 10-round junior middleweight scrap and unbeaten welterweight Errol Spence Jr. (14-0, 11 KOs), of Desoto, Texas, will take on Javier Castro (27-7, 22 KOs), of Chihuahua, Mexico, in an 8-round fight.  Also, former world champion “Vicious” Victor Ortiz (29-5, 22 KOs), of Ventura, Calif. will battle Denver’s Manuel Perez (21-10-1, 4 KOs) in a scheduled 8-round match that will be featured on the SHOWTIME BOXING on SHO EXTREME telecast.