Juan Martin del Potro has suffered a second fracture in his right knee in the past year, a spokesman for the Argentine tennis player tweeted Thursday.
Del Potro withdrew from the Queen's Club grass-court event Wednesday after injuring his knee during a 7-5, 6-4 win over Denis Shapovalov in the first round. Del Potro finished the match with pain and swelling in his right knee after slipping near the net in the eighth game of the second set.
"The medical studies done last night in a clinic in London show that Juan Martin del Potro has suffered again a fracture in the right patella," Jorge Viale wrote. "After consultation with his doctor, Angel Cotorro, it has been determined that it will require surgery."
Viale wrote that Del Potro will undergo surgery in "the next couple of days."
The No. 12-ranked Del Potro previously fractured his knee at the Shanghai Masters in October. He has played in five tournaments this year, including a fourth-round exit at the French Open.
The Associated Press contributed to this report.