(CNN) -- Argentina's Juan Martin del Potro became the second player in the world's top 10 to withdraw from the French Open when a viral infection ruled him out of Sunday's championships in Paris.
The world No. 7 revealed that the virus had affected him when losing to Frenchman Benoit Paire in last week's Rome Masters.
The 24-year-old's withdrawal follows that of world No. 2 Andy Murray, who pulled out of the year's second grand slam with a back injury.
"This is a tough blow, because these are the events you dream of winning," said del Potro, who won the U.S. Open in 2009, on the ATP website.
"Now I must get over this disappointment and recover completely in order to prepare at 100% for the tests to come."
The virus affecting Del Potro had prompted the tall right-hander to miss recent tournaments in Portugal and Madrid, and he returned in Italy with the hope of being able to compete at the French Open.
Despite his exit in the third round, he will always remember his time in the Italian capital after meeting with the Pope, a fellow Argentine, last week -- an experience del Potro said he would "never forget".
Del Potro reached the semifinals of Roland Garros in 2009 and the quarterfinals last year -- only to be beaten by Roger Federer on both occasions.
He was joined in withdrawing from next week's event by former world number seven Mardy Fish, who is now ranked 41st in the world, and fellow American Brian Baker -- whose absences had been expected.
Also on Wednesday, Caroline Wozniacki's terrible 2013 continued when the number one seed was beaten in straight sets by China's Zheng Jie at the Brussels Open.
The former world number one from Denmark is on a terrible recent run of form, having now added a first round exit in Brussels to those suffered in Italy, Spain and Germany in the last month alone.
The latest loss was all the more humbling given that Zheng had been on court four hours earlier to see off American qualifier Mallory Burdette in the first round.
Wozniacki, who had received a bye into the second round, was beaten by Zheng's aggressive tactics with the Chinese hitting twice as many winners as the Dane (34 to 17).
"She's a very tough player and fought until the last point," Zheng was quoted as saying by the Women's Tennis Association website.
"I'm so happy I could win this match. We've played many times before and she's always so tough to beat.
"But she's also a very nice person, ever since she was a junior. I'm very proud and this gives me a lot of confidence."
Zheng will play Romina Oprandi of Switzerland in the quarterfinals, while Wozniacki must work out how to rediscover the form that took her to April's Indian Wells final ahead of Sunday's French Open.