Canelo Alvarez's camp is "engaged in serious discussions and nearing a deal" to fight Sergiy Derevyanchenko, one of his mandatory IBF challengers, ESPN.com reported, citing unidentified sources with knowledge of the negotiations.

The sides are negotiating for Alvarez to make the mandatory defense of his IBF middleweight title in October or November, BoxingScene.com reported, citing multiple unidentified sources. 

The talks between the two camps are so serious that a purse bid that had been scheduled for noon ET Tuesday at the IBF offices in New Jersey was postponed to Friday.

If he doesn't fight Derevyanchenko (13-1, 10 KOs) next Alvarez (52-1-2, 35 KOs) will be stripped of the 160-pound belt.

Although Alvarez, 28, has forfeited titles in the past, he has spoken openly in recent months about wanting to become the undisputed middleweight champion by holding all four major belts at the same time.

A complicating factor: Sports streaming service DAZN, which in 2018 signed Alvarez to a five-year, 11-bout, $365 million deal, wants him to fight former unified champion Gennady Golovkin a third time. (DAZN also signed Golovkin to a six-fight, nine-figure deal earlier this year.) Per ESPN: Alvarez isn't opposed to a third Golovkin fight but doesn't want to face him next, however DAZN must approve Derevyanchenko as an opponent.

Derevyanchenko, 33, built his reputation as an amateur, representing Ukraine at the 2008 Olympics, but suffered his lone loss in October in New York by split decision to Daniel Jacobs for the vacant IBF title. Derevyanchenko bounced back in April to win a unanimous decision against Jack Culcay in a title elimination bout to become the IBF's mandatory challenger again.

Jacobs then lost to Alvarez by unanimous decision in May, setting up the mandatory IBF defense against Derevyanchenko.