Jermall Charlo to defend interim middleweight belt vs. Matt Korobov

Jermall Charlo will defend his interim middleweight belt against late replacement Matt Korobov on Saturday night at Barclays Center in Brooklyn, New York, Premier Boxing Champions announced on Monday.

Charlo was due to make his first defense against Willie Monroe Jr. in the main event of the PBC on Fox card, the first under their new rights deal. However, Monroe tested positive in recent days for a banned substance in a WBC Clean Boxing Program test administered by the Voluntary Anti-Doping Association.

With the New York State Athletic Commission ruling Monroe out of the fight and the WBC, which sanctions Charlo's belt, refusing to sanction the bout, Monroe was dropped in favor of Korobov, who was already scheduled to fight in an eight-round bout against Juan De Angel on the undercard.

"The WBC will afford Mr. Monroe the due process to which he is entitled under the WBC CBP's protocol. While the WBC follows its protocol's procedures, Mr. Monroe's situation cannot be fully and justly adjudicated on a timely fashion for him to fight for the WBC title," the sanctioning body said in a statement. "The WBC CBP's ultimate goal is to protect the health, safety and welfare of boxers. Accordingly, the WBC must fully investigate the specific facts surrounding Mr. Monroe's reported adverse finding before fully adjudicating the matter.

"At this point, the facts known to the WBC indicate that a sample collected from Mr. Monroe yielded an adverse finding for a banned steroidal substance. It also appears that Mr. Monroe disclosed to the sample collector his use of a non-specific 'testosterone booster' in his doping control form. Mr. Monroe did not request, nor did he receive, a therapeutic use exception for any substance."

Once word of Monroe's failed drug test came out on Saturday, Korobov sought out the bout with Charlo.

"I was training to fight on this card so I am physically and mentally ready to fight,'' Korobov said. "It doesn't matter that I am taking this fight on a week's notice because I have been preparing for this moment my entire life. I will make a few adjustments for Charlo and make the most of this opportunity."

Korobov's fight with De Angel was contracted at 162 pounds, so he will need to lose two more than he planned to in order to get down to the middleweight limit of 160.

The southpaw Korobov (28-1, 14 KOs), a 2008 Russian Olympian now fighting out of St. Petersburg, Florida, suffered his only defeat in a world title fight. He challenged Andy Lee for a vacant middleweight belt in December 2014 and was winning handily when Lee knocked him out with a right hook in the sixth round.

Korobov has been very inactive since, boxing only four times, most recently in a six-round decision win in March as a light heavyweight. Korobov's biggest win is a 10-round decision in June 2014 against Jose Uzcategui, who went on to win a super middleweight world title.

Charlo (27-0, 21 KOs), 28, of Houston, was already preparing to fight a southpaw in Monroe (23-3, 6 KOs), 32, a former two-time world title challenger from Rochester, New York, so he said he was fine with the change of opponent.

"I was well prepared for Willie Monroe, who is a southpaw, so there won't be that much difference facing Korobov,'' Charlo said. "There is a size difference. He's taller than Monroe, but I'll just have to adjust my game plan. The best fighters in the world are the ones who are able to make the best adjustments. Beating Korobov is going to make the victory that much sweeter due to this adversity.

"That means the celebration is going to be sweeter as well. He was fighting on the undercard, so he's prepared. But now fighting for the [interim] title in the top spot is going to make him fight harder. I love it. He's a much better opponent on paper than Willie Monroe Jr."

The PBC on Fox tripleheader (8 p.m. ET) also will include Jermell Charlo (31-0, 15 KOs), Jermall's twin brother, defending his junior middleweight world title against Tony Harrison (27-2, 21 KOs), and heavyweight contender Dominic Breazeale (19-1, 17 KOs) taking on Carlos Negron (20-1, 16 KOs) in a scheduled 10-rounder.