Middleweight world champion Canelo Alvarez is not getting much time to enjoy his unanimous decision victory over Daniel Jacobs in their world title unification fight that took place on May 4 in Las Vegas.

On Wednesday, less than two weeks after the fight, the IBF, whose belt Alvarez won from Jacobs to add to his two titles, ordered Alvarez to next make a mandatory defense against No. 1 challenger Sergiy Derevyanchenko.

In a letter sent via email to Robert Diaz of Golden Boy Promotions, Alvarez's promoter, the IBF informed the company and Alvarez that the mandatory title defense is "due on or before Aug. 4" and gave them contact information for Derevyanchenko promoter Lou DiBella to begin talks.

"Negotiations should commence immediately and be concluded by June 15, 2019," the IBF wrote.

If the camps don't make a deal by the deadline, the IBF will order a purse bid with the highest bidder gaining promotional control of the fight.

Middleweight world champion Canelo Alvarez has a decision to make after being ordered to defend his IBF title against No. 1 challenger Sergiy Derevyanchenko. AP Photo/John Locher

It is unclear what Alvarez, who has yet to receive his belt from the IBF, will do next, but he will not fight on or before Aug. 4. He might be able to get an extension from the IBF, but Alvarez's next fight is penciled in for Sept. 14, the weekend of Mexican Independence Day on which he usually fights.

Also, Alvarez and Golden Boy, as well as DAZN, their broadcast partner, would like to see what happens with former unified champion Gennady Golovkin's fight against Steve Rolls on June 8 before committing to any other bout because of the demand for a third fight between Alvarez and GGG.

Alvarez (52-1-2, 35 KOs), 28, of Mexico, has said that he wanted to make 2019 the year in which he unified the four major belts in the 160-pound weight class, so he will also be paying attention to the fight between world titlist Demetrius Andrade and Maciej Sulecki, which takes place June 29 in Andrade's hometown of Providence, Rhode Island.

"It's really surprising and unfortunate that we didn't get a congratulations letter [from the IBF] like we would in the past," Golden Boy Promotions president Eric Gomez told ESPN. "We will be meeting with Canelo in the next week or so to see what he would like to do."

Derevyanchenko (13-1, 10 KOs), 33, a 2008 Olympian for Ukraine who fights out of Brooklyn, New York, got a shot at the vacant IBF belt on Oct. 27 and lost a split decision to longtime training partner Jacobs, who went on to the unification fight with Alvarez in his next bout. Derevyanchenko bounced back from the defeat to win a unanimous decision over Jack Culcay in a title elimination fight for the mandatory position on April 13.

"Now that the IBF has ordered immediate negotiations between the two sides, I will sit down with Sergiy, [adviser] Al Haymon and Lou DiBella next week and talk about the best course of action," Keith Connolly, Derevyanchenko's manager, told ESPN.