Abner Mares and Jermall Charlo have been added to a Showtime-televised quadrupleheader on Dec. 13 at the MGM Grand in Las Vegas, Golden Boy Promotions president Oscar De La Hoya announced on Tuesday.

A three-division titlewinner, Mares (27-1-1, 14 knockouts) will face Jose Ramirez (24-3-2, 15 KOs) on a card that has been dubbed “Royal Battle” and is headlined by former titleholders Amir Khan and Devon Alexander in a welterweight bout.

Also part of the four-fight Showtime telecast, to begin at 9 p.m. ET/6 p.m. PT, will be a co-feature with Keith Thurman and Leonard Bundu facing off in a 147-pound clash of unbeatens, with the opening bout of the broadcast matching undefeated Jermall Charlo in a junior middleweight clash against Italy’s Lenny Bottai.

Starting at 7 p.m. ET/PT (delayed on the West Coast), Showtime Extreme viewers will be treated to a 154-pound bout matching unbeaten Jermell Charlo, the 24-year-old twin of Jermall Charlo, against Mario Alberto Lozano.

Also on Showtime Extreme will be undefeated welterweight Erroll Spence Jr., a 2012 United States Olympian, opposite Mike Arnaoutis, as well as former welterweight beltholder Victor Ortiz will face Manuel Perez.

In non-televised bouts, former WBA light heavyweight titleholder Beibut Shumenov will make his cruiserweight debut against Bobby Thomas, and junior middleweight Yoshihiro Kamegai of Tokyo will face Oscar Godoy.

Originally announced as a Showtime tripleheader last month that was to include Jermell Charlo against undefeated WBO 154-pound titleholder Demetrius Andrade, the card had to be restructured after Andrade pulled out of the fight due to monetary issues.

KHAN-ALEXANDER

In his last fight in May, Khan (29-3, 19 KOs) scored a one-sided unanimous decision over former welterweight titleholder Luis Collazo, whom he floored three times.

Khan, 27, had been out of the ring for more than a year prior to the Collazo fight, last being in action for a unanimous decision over two-time lightweight titleholder Julio Diaz in April 2013. Khan struggled over the course of his previous six fights, going 4-2 with two knockouts.

Alexander (26-2, 14 KOs) is coming off a unanimous decision victory over Jesus Soto Karass at in June. The 27-year-old contender had previously faced seven current or past world titleholders in his last nine fights, a run that includes decision victories over two of Argentina’s most devastating punchers ÔÇö Marcos Maidana and Lucas Matthysse.

Alexander’s only losses are to two-division titlewinner Timothy Bradley and former IBF titleholder Shawn Porter.

THURMAN-BUNDU

Thurman (23-0, 21 KOs) scored his third straight stoppage win in April, doing so in the third round over two-time lightweight beltwinner Julio Diaz. Thurman, 26, has stopped 11 of his past 12 opponents.

A resident of Italy who was born in Sierra Leone, Bundu, 40, will be fighting on American soil for the first time against Thurman. Bundu (31-0-2, 11 KOs) has scored knockouts in four of his past six victories and has held the European welterweight title since June 2011.

A split decision victory over Frankie Gavin in August ended Bundu’s run of three consecutive stoppage wins and represented his third triumph over a previously undefeated fighter in his past eight appearances.

MARES-RAMIREZ

In his last fight in July, Mares, 28, survived a cut over his left eye en route to a unanimous decision win over rugged Jonathan Oquendo. Oquendo represented Mares’ first fight since August 2013, when he was dethroned as WBC featherweight titleholder in a shocking first-round knockout loss to Jhonny Gonzalez, who floored him twice.

Ramirez, 27, is 5-4 with two knockouts over the course of his past nine fights, and was last in the ring for a fourth-round stoppage loss to Vasyl Lomachenko in October 2013. The loss to Lomachenko ended Ramirez’s three-fight winning streak.

CHARLO-BOTTAI

In his last fight in September, Charlo registered his 13th consecutive stoppage win, doing so in the fourth round over Norberto Gonzalez, whom dropped in the fifth round.

Coming off a split-decision win over Ismael El Massoudi in March, Bottai, 37, has won seven consecutive fights, four by stoppage, since falling by ninth-round knockout to Jean Michel Hamilcaro in October 2011.

The loss to Hamilcaro ended a four-fight winning streak for Bottai (22-2, 9 KOs), whose other setback was by majority decision to Francesco Di Fiore in July 2010.

LIGHTWEIGHT JAIRO LLANES SIGNS WITH SAMPSON LEWKOWICZ

Lightweight Jairo “Jimmy” Llanes (7-0-1, 6 KOs), of Los Mochis Sinaloa, Mexico, has signed a promotional agreement with Sampson Lewkowicz of Sampson Boxing, Lewkowicz announced on Tuesday.

“Jimmy is a very talented prospect and is already very popular in his native Los Mochis. He is the third fighter brought to me by my trusted advisor in Mexico, Fernando Dominguez from Dominguez Promotions,” said Lewkowicz of Llanes, 20, who will be in action on Dec. 5 against Mao Corona (5-3-1, 2 KOs) in Mexico.

“Fernando is my right-hand man in the country and he says this young fighter has what it takes. I’m happy to be working with Jimmy and I predict big things for his future. We will bring him along at the right speed and help him become the next great fighter to come from Mexico.”

EVANDER HOLYFIELD SPOOFS HIS RETIREMENT

Five-time heavyweight champion Evander Holyfield has been ambivalent about retirement, informed RingTV.com at one point that, “I’m done” only to say, later, “I have the right to change my mind.”

Holyfield, who turned 52 in October, spoofed his status during a humorous commercial for HD Tracks, a high resolution music store.

Click here for the video.