Injury-plagued Juan Martin del Potro on Wednesday underwent a third surgery on the right knee he broke at the 2018 Shanghai Masters, his press spokesman said.
The 31-year-old Argentine giant has now had seven major operations in his career which promised so much when he swept to his first and only Grand Slam title at the 2009 US Open.
"In recent months, Delpo followed his doctors' advice and even tested the knee on a tennis court in Buenos Aires, but the pain persisted," said a statement.
"After their first meeting in Bern, Switzerland, (his surgeon) recommended a new surgery."
Del Potro, a former world number three but now down at 132 in the rankings, hasn't played since Queen's Club on the eve of Wimbledon in 2019.
As well as three knee operations, he had surgery on his right wrist in 2010 and three procedures on his left wrist in March 2014, January 2015 and June 2015.