Stan Wawrinka has withdrawn from the Rio Olympics with a back injury, the Swiss Tennis Federation announced Tuesday.
Wawrinka aggravated his back playing in the Rogers Cup last week. He has been ruled out of competition indefinitely by doctors.
Wawrinka, 31, entered the Olympics ranked No. 4 in the world.
"I am very sad because I would like to have witnessed my third Olympic Games,” Wawrinka, who competed in Beijing and London, said in a statement. “Unfortunately, this will not be possible now. I wish all Swiss athletes I support, of course, good luck in Rio."
Wawrinka joins Roger Federer, Milos Raonic, Tomas Berdych and Dominic Thiem among notable men’s players to withdraw from the upcoming games.