Former lightweight champion Vasiliy Lomachenko underwent right shoulder surgery on Monday, according to ESPN's Steve Kim.
Lomachenko surrendered his WBC, WBO and WBA lightweight titles in a loss to Teofimo Lopez on Saturday. Lomachenko battled shoulder pain throughout the fight before losing the bout in a second-round decision.
"When [Lomachenko] arrived to the States to prepare for the fight, he said in the Ukraine he felt the sharp pain in his right shoulder," Egis Klimas, Lomachenko's trainer said. "We took him right away to Dr. ElAttrache to examine him."
Lomanchenko expects to resume training in January.