“I announce that I will not be competing in the 2016 Summer Olympic Games this coming August in Rio de Janeiro,” the Australian, 28, wrote in a statement published on his official Twitter account.
“The reason for my decision is my concerns about the possible transmission of the Zika virus and the potential risks that it may present to my wife’s future pregnancies and to future members of our family,” the father of two added.
He also said that even though competing at the Olympics was his “major goal,” he would never place it before the safety of his family.
Day added that he had already informed his coach Baker Finch and the CEO of Golf Australia about his decision.
The world number one made his announcement at the World Golf Championships-Bridgestone Invitational event in Akron, Ohio, on Tuesday.
Medical experts have confirmed that while perhaps slight, a decision to compete in Rio absolutely comes with health risks to me and to my family,” he said.
The Australian Olympic Committee and Golf Australia are yet to comment on Day’s decision.
Day becomes the second major golf star to withdraw from the Olympics in recent weeks, following Irish four-time major winner Rory McIlroy, who announced on June 22 that he is “unwilling to take the risk of infection from Zika virus” and thus will not compete in Rio.
Golf is returning to the Olympics in Rio for the first time following a 112-year absence.
Other players who earlier pulled out of the event for similar reasons include Adam Scott and Marc Leishman from Australia, Vijay Singh from Fiji, as well as South Africans Charl Schwartzel and Louis Oosthuizen.
Golfers are not the only athletes to have decided to miss the Games, as the event has been hit by a string of withdrawals across numerous sports. NBA stars Steph Curry, Russell Westbrook and LaMarcus Aldridge have all announced they will sit out the event, while Antony Davis, Chris Paul and Blake Griffin are other confirmed absentees.
American cyclist Tejay van Garderen – whose wife is pregnant – has also pulled out, with tennis players John Isner, Dominc Thiem, Feliciano Lopez, Bernard Tomic and Nick Kyrgios also not traveling to Brazil.
Zika is a mosquito-borne virus that has been found to cause underdeveloped brains in babies born to women infected while pregnant. It’s also potentially linked to neurological disorders in some infected children and adults.
There are currently no vaccines or drug treatments for Zika, a disease that the US National Institutes of Health says has reached pandemic levels in the Americas. A new vaccine was approved for human clinical trials by the US Food and Drug Administration (FDA) on June 20.
In May, more than 150 medical specialists from various countries even urged the World Health Organization (WHO) to advise the International Olympic Committee (IOC) to postpone or move the Olympics from Brazil to another country over Zika concerns – although the WHO rejected the idea.
Meanwhile, Rio 2016 chief executive Sidney Levy said that fears over the Zika virus are “overblown” as he spoke to the BBC on Monday.