A torn labrum in his right shoulder will force lightweight world champion and pound-for-pound king Vasiliy Lomachenko to undergo arthroscopic surgery on Wednesday in Los Angeles. 

Lomachenko's promoter, Bob Arum of Top Rank, confirmed the news Tuesday with ESPN. According to the fighter, the injury occurred during Round 2 of his May 12 victory over Jorge Linares, won via dramatic 10th-round TKO, when his right shoulder popped out of place before popping back in and causing discomfort. 

"I couldn't use my right arm, throw my right hook, and it was very uncomfortable to continue my fight," Lomachenko told ESPN following his examination by orthopedic surgeon Dr. Neal ElAttrache at the Kerlan Jobe Orthopedic Clinic.

The injury pushes back Arum's initial hope that Lomachenko (11-1, 9 KOs), the WBA champion, would return in Los Angeles on Aug. 25 in a possible lightweight unification bout against WBO champion Ray Beltran. 

ElAttrache, who will perform the 60- to 90-minute procedure, believes Lomachenko could resume training as early as October and be ready to fight in December following rehabilitation. Arum said Lomachenko, if all goes well, could headline a Top Rank card on Dec. 8.

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"There is clear evidence that he had a recent dislocation of the shoulder, and the most common injury that happens when there is a dislocation is a tear in the labrum," ElAttrache said. "His is pretty extensive. A typical tear usually goes from about 2 o'clock if you're looking at the face of a clock down to about 6 o'clock. His goes almost all the way around. I would say he has significant instability of his right shoulder."

The team doctor for the Los Angeles Dodgers and Rams, ElAttrache has performed prior surgeries on boxers Manny Pacquiao (following his 2015 loss to Floyd Mayweather), Vitali Klitschko and Andre Berto, along with the likes of Kobe Bryant and Tom Brady. 

Lomachenko, 30, made history against Linares by winning his third world title in as many divisions in just his 12th pro fight. He previously tied the record for the fewest fights needed to win a world title (three) and set his own mark by needing just seven fights to win titles in two weight classes. 

Both Arum and Lomachenko's manager, Egis Klimas, revealed that the two-time Olympic gold medalist from Ukraine has dealt with minor right shoulder pain in the past. 

"Every once in a while when he would spar, he'd have pain in the shoulder but then he'd ice it and then there'd be no problem," Arum said. "But this time it was different with the pain he was having in the fight and after the fight. So, obviously, Aug. 25 is out for his next fight and we're looking at Dec. 8. If the shoulder doesn't come around in time we'll have to postpone it, but we're looking at him being ready to go Dec. 8. But we know there are no guarantees."