After concerns about the international spread of the Zika virus, 150 of the World Health Organization’s scientists signed an open letter asking for the games to be cancelled or at least postponed.

Due to the recent Zika virus outbreak in Rio de Janeiro, Brazil, around 400,000 tickets remained unsold, with attendees and athletes who originally planned to attend the Olympic Games deciding to forego the Games.

Tennis athletes including Milos Raonic, Canada; Simona Halep, Romania; and Nick Kyrgios, Australia, did not attend.

Jordan Spieth, USA; Rory McIlroy, UK; and Dustin Johnson, USA, are among the golf athletes who refused to participate.

For cycling, Tejay van Garderen, USA; Alberto Contador, Spain; and Simon Gerrans, Australia, were not in attendance for the Games.

Finally, basketball athletes Stephen Curry, USA; and LeBron James, USA, did not attend.