Gennady Golovkin (37-0-1, 33 KOs) may have a problem if he intends to fight Canelo Alvarez in the fall - because the International Boxing Federation has ordered him to make a mandatory defense against Sergiy Derevyanchenko (12-0, 10 KOs).

The sanctioning body allowed Golovkin to face late replacement Vanes Martirosyan on May 5th at the StubHub Center in Carson, California - but he must face Derevyanchenko next or risk losing his title.

Vanes stepped in less than two weeks ago after Canelo withdrew from the contest, following a positive drug test for the banned substance clenbuterol. The Mexican superstar also received a suspension from the Nevada State Athletic Commission.

Golovkin, who has the IBF, IBO, WBA, WBC world titles, is very close to unifying the entire weight class - which has been his goal for several years.

But if he doesn't make his mandatory next, he will lose the IBF title.

Golovkin must agree in writing, before the contest with Vanes takes place, to fight Derevyanchenko within 90 days (by August 3) or he will be stripped of the belt.

If Golovkin does not agree to these terms by next Friday, the contest with Vanes will not receive an exception and he will risk losing the title.

Canelo is only serving a six month suspension and plans to fight again in September, during Mexican Independence Day weekend.

It is widely believed that Canelo vs. Golovkin II would take place in the fall, but the IBF's recent order has placed that contest in doubt.

Canelo and Golovkin fought to a controversial twelve round split draw last September at the T-Mobile Arena in Las Vegas.

Vanes could upset the odds and create an entirely different scenario, but very few expect him to win - because he's taking the fight on late notice, he's moving up from junior middleweight, and he's been out of the ring for nearly two years.