Jordan Spieth has become the latest high-profile golfer to pull out of this summer's Olympic Games in Rio de Janeiro.
The 22-year-old has withdrawn from the Games due to concerns over the Zika virus, which has been linked to defects in newborn babies, and will be replaced in the American team by Matt Kuchar.
Spieth's decision means that the world's top four golfers will not be present in Rio, with Jason Day, Dustin Johnson and Rory McIlroy already having withdrawn.
"We do understand why these individual decisions have been made," International Golf Federation president Peter Dawson is quoted as saying by BBC Sport.
"Personally, I think there's been something of an overreaction to the Zika situation, but that's for individuals to determine, and there's certainly a great deal of concern about this issue inside the game of golf."
Golf is making its first appearance at the Olympics since 1904 this summer.
