Branden Grace has become the latest golfer to pull out of the summer Olympics in Rio over fears around the Zika virus.
The 28-year-old South African cited his upcoming marriage and his desire to start a family as the main reasons.
"I am getting married in November and hoping to start a family. I must put their health first," he said.
"I really hope to be able to qualify again in four years' time."
Grace follows Northern Ireland duo Rory McIlroy and Graeme McDowell, who have already pulled out, as well as Fiji's Vijay Singh and Marc Leishman of Australia.
World No 1 Jason Day, meanwhile, says he is still considering his options.
Golf is returning to the Olympics for the first time since 1904.
Zika is a mosquito-borne virus which has been linked to brain defects in newborn babies.