There should be no reason why unified middleweight champion Gennady Golovkin does not fight Sergiy Derevyanchenko next month, according to the latter's promoter Lou DiBella.

Golovkin (37-0-1) still plans on defending his World Boxing Association (WBA), World Boxing Council (WBC), International Boxing Federation (IBF), and International Boxing Organization (IBO) middleweight titles after his scheduled rematch with Canelo Alvarez was canceled.

The two middleweights were set to clash once again on May 5 in Las Vegas, Nevada, after their first encounter in September last year ended in a controversial split-decision. However, the Mexican withdrew from the contest last week after a formal complaint was filed against him by the Nevada State Athletic Commission (NSAC) following two failed drug tests for clenbuterol in February.

While Golovkin's promoter Tom Loeffler recently revealed a number of opponents are being considered, Gary "Spike" O'Sullivan seems to be the likely candidate, according to WBC President Mauricio Sulaiman.

The development was not received well by DiBella, who promotes Golovkin's IBF mandatory challenger Derevyanchenko (12-0), as he believes a withdrawal should not "stop a mandatory from happening" along with the fact that the Ukrainian fits the requirement of not being a southpaw fighter as mentioned by Loeffler.

DiBella also believes "GGG" views facing his fighter as a risk, especially with the lucrative Canelo rematch now likely to take place in September this year.

"I don't understand saying that extenuating circumstances allow something different," DiBella told the Los Angeles Times on Monday. "Is the extenuating case that he doesn't want to take a risk? That's what it seems like to me."

"What is wrong with switching to another conventional, right-handed fighter who comes forward? How can he not be prepared for Sergiy Derevyanchenko? And our guy is in the gym and ready to fight. So I don't understand any argument against him," he said. "When a guy is sitting in a mandatory spot, he's not getting paid until he gets that [title] fight. And if Golovkin faces Canelo next, this decision could affect [Derevyanchenko] for 18 months."

Sulaiman, though, believes it is unfair to enforce a mandatory challenger for Golovkin on such short notice and is fine with him facing Canelo once the latter is clear to fight again, especially as the reason for the cancellation was not his fault.

"How can you penalize Golovkin when the fight has to happen within a month?" Sulaiman was quoted as asking. "You have to support your champion. It'd be so unfair to penalize him now when, for reasons out of his control, his fight [with Alvarez] is off. We'll support him and allow him to proceed to Canelo."

According to the LA Times, a Tuesday morning conference call is scheduled involving Sulaiman, IBF President Daryl Peoples and WBA head Gilberto Mendoza as the trio will discuss the Kazakhstan fighter's next clash.

Derevyanchenko last fought in March this year when he finished Dashon Johnson in the sixth round of their middleweight contest in Brooklyn, New York.