Recently dethroned lightweight champion Vasiliy Lomachenko underwent right shoulder surgery Monday, according to his manager, Egis Klimas.

Lomachenko previously had surgery on his right shoulder in May 2018. Klimas said this surgery was a result of both a pre-existing ailment and an injury suffered during the second round of Saturday night's decision loss to Teofimo Lopez.

Lomachenko was very cautious in the first half of the contest, when Lopez built a significant lead on the scorecards. His late-rounds rally fell short, and Lomachenko lost his WBC, WBO and WBA titles.

He was examined Monday by Dr. Neal ElAttrache (who also oversaw his operation in 2018) and was told he would need surgery that day.

Lomachenko should be able to resume training by mid-January, according to Klimas.

"When he arrived to the States to prepare for the fight, he said in the Ukraine he felt the sharp pain in his right shoulder," said Klimas, who noted that an MRI didnt reveal any significant injury to the shoulder. "We took him right away to Dr. ElAttrache to examine him."

At six weeks out from the fight, Lomachenko was given an injection and alerted both the Voluntary Anti-Doping Association and the Nevada State Athletic Commission.

"We lost one week of training. We lost one week of sparring because the doctor forbid him to do much for a week after the injection," Klimas said.

Klimas added that a few weeks later the pain flared up again during a sparring session. At that juncture, Lomachenko was given another injection and his father and trainer, Anatoly, "wanted out of the fight," said Klimas.

Vasiliy Lomachenko said he would not pull out of the fight and made it clear to his team that if he dropped out, he would retire.

While news of the injury came out quickly after Saturday's loss, Klimas insisted: "We didn't want to look like we were looking for excuses or something."

When Lomachenko heals up, Klimas says he wants a chance to get back the belts.

"If it's possible, we would like to have the rematch," Klimas said. "If they are so tough ... are they willing to come back and do that?"