Milos Raonic, the finalist at Wimbledon this year, and women's world number five Simona Halep of Romania have pulled out from next month's Rio Olympics due to fears over the Zika virus.
They, along with twice Australian Open champion Victoria Azarenka, who is pregnant, will not be making the trip to Rio even though they were included in the final list of participants issued by the International Tennis Federation (ITF) on Friday.
The big-serving Raonic, who lost to Andy Murray in the men's championship match at the All England Club on Sunday, was the first tennis player to pull out of the Aug 5-21 Olympics due to concerns over the mosquito-borne Zika virus.
"It is with a heavy heart that I am announcing my withdrawal from participation in the Rio 2016 Olympic Games," world number seven Raonic, 25, said in a statement issued by Tennis Canada.
"After much deliberation with my family and coaches, I am making this decision for a variety of health concerns including the uncertainty around the Zika virus."
The Zika virus, which the World Health Organisation says is spreading rapidly in the Americas, has been linked to severe birth defects in infants born to infected women, and possible neurological problems in adults.
Halep, who last month told Reuters she was "very worried" about the long-term effects of the Zika virus, consulted with many doctors before issuing her decision shortly after Raonic.
"I regret to announce that I have decided I will not compete in the Olympic Games. The reason for my decision is the concern regarding the danger posed by the Zika virus," Halep, a runner-up at the French Open in 2014, said on her Facebook page.
"After several talks with doctors and my family, I concluded that the risks are too high for my career and for my health, especially as a woman. Family is much too important for me and I can’t risk not being able to have one of my own after my career in tennis is over.
"I know the Olympics are a very important event and I truly regret these circumstances. I hope the Romanian Olympic and Sports Committee and all Romanians will respect my decision.
"I will continue to play, to proudly represent Romania in as many tournaments as possible."
Raonic and Halep joined a growing list of athletes to have pulled out of the Rio Games over health concerns triggered by the outbreak of the Zika virus in Brazil, including a number of high-profile male golfers.
Belarussian Azarenka also robbed the Olympics of some star power as the world number six said earlier on Friday that she will miss the rest of the season because she is having a baby.
Raonic, beaten in the second round of the 2012 London Games by Frenchman Jo-Wilfried Tsonga, said he hopes his decision would not influence others.
"This was a difficult, personal choice and I do not wish for it to impact the decision of any other athlete heading to the Games," said Raonic.
"I am very proud to have competed for Canada at the London 2012 Summer Olympics, and on the world stage at several Davis Cup events. I look forward to cheering on Team Canada this summer."
Image: Canada's Milos Raonic celebrates after beating Roger Federer
Photograph: Tony O'Brien/Reuters