The knee surgery that Mexican superstar Canelo Alvarez underwent Mexico was a little more serious than initially reported.

Golden Boy Promotions president Eric Gomez told ESPN Deportes that the surgery was nothing more than “cosmetic,” but according to Canelo, that was not the case.

Instead, a cyst was taken out of his knee.

“I share that today I had to undergo an arthroscopic surgery to repair the internal femoral cartilage and eliminate a pathological fold of my right knee,” Alvarez said on Instagram in comments translated from Spanish. “I dismiss the erroneous information published by Golden Boy president Eric Gomez. Thanks for worrying!! And in three to four weeks I’ll be like new.”

Alvarez was slated to fight unified middleweight titleholder Gennady Golovkin on May 5 at T-Mobile Arena in Las Vegas in a rematch of their highly disputed draw from last September that most ringside observers believed Golovkin had won.

But Alvarez tested positive for trace amounts of the banned substance clenbuterol in random urine tests conducted by the Voluntary Anti-Doping Association on Feb. 17 and Feb. 20. As a result, he was temporarily suspended by the Nevada State Athletic Commission, and eventually withdrew from the highly-anticipated bout on April 3.

A replacement opponent has yet to be announced, but for now, Golovkin is still expected to fight on May 5 at StubHub Center in Carson, California on regular HBO.

Information provided by FightNights.com