TROON, Scotland » Golf waited 112 years to get back into the Olympics. The top four players in the world are waiting a bit longer.

Jordan Spieth delivered the final blow today when he told the International Golf Federation he would not be going to Rio next month, leaving the sport without its four highest-ranked players who have captured six of the last eight majors.

IGF President Peter Dawson said Spieth cited his concern over “health issues” for withdrawing.

All have indicated support for 2020 in Tokyo.

Jason Day, Dustin Johnson and Rory McIlroy previously withdrew, all citing the Zika virus. Day and Johnson have said they plan on having more children, while McIlroy is engaged and said he would soon be starting a family.

Eighteen eligible men, based on today’s world ranking, withdrew from the Olympics.

The women only had one player withdraw, Lee Anne Pace of South Africa, due to Zika concerns.

The men will have eight of the top 15 in the world in Rio. The women will have the top nine in the world; Ha-Na Jang at No. 10 is not eligible because South Korea already reached its maximum of four players.

“There is no doubt that the number of withdrawals hasn’t shed golf in the best light, and we have to accept that,” Dawson said. “But we do understand why these individual decisions have been taken. 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, no doubt about that.”

Spieth was playing a practice round at Royal Troon for the British Open when the IGF held its news conference to announce who qualified. Spieth was not expected to speak until Tuesday. When he finished his round, he went back toward the gallery to sign autographs, and then walked across the front of the 18th green to the other side toward the parking lot.

Golf pulled out all the stops to get back into the Olympics, presenting on video the support from some of the best players in the world at the time — Tiger Woods, Phil Mickelson, Ernie Els, Lorena Ochoa, Suzann Pettersen — when it was voted onto the program in 2009.

Spieth was among the most enthusiastic until about a month ago when he joined others in expressing concern about Zika, security and other issues facing the Rio Games. He was said to be torn about playing until deciding this morning not to go.

Losing the top four could be a big setback for men’s golf and its bid to stay in the Olympics. It is assured of being part of the Tokyo Games in 2020, but the International Olympic Committee votes next year on whether golf and other events stay beyond that.

Dawson said he felt certain the IOC would consider all things Rio when it meets next year.

“We’re always concerned, but we’re working damned hard to put our best foot forward,” he said. “We have a lot of professional people in golf, and you can guarantee the sport will be shown in its best light.”

NBC Sports Group Chair Mark Lazarus today called the withdrawals “surprising and disappointing.” The sport’s return to the Olympics, which NBCUniversal networks broadcast in the U.S., offered a showcase for its Golf Channel.

Lazarus noted the number of top players who will still be there and said “we expect a great competition.”

Other players who were eligible but not listed among the 60-player field were Victor Dubuisson of France, K.T. Kim of South Korea, Matt Jones of Australia and Hideto Tanihara of Japan. All of those countries still have the maximum two players in Rio. Countries are allowed up to four provided they are within the top 15 in the world.

For the women, Gerina Piller tied for eighth in the U.S. Women’s Open on Sunday, enough to move the American up one spot to qualify. She will join Lexi Thompson and Stacy Lewis for the U.S. South Korea was the only country for the women with four players, all among the top nine.

Spieth’s spot went to Matt Kuchar, who only moved to No. 15 in the world ranking by making a 12-foot birdie on the final hole of a World Golf Championship in Ohio two weeks ago. The other Americans will be Bubba Watson, Rickie Fowler and Patrick Reed, who replaced Johnson.

No other country had more than two players for the men.

The Olympics will be represented by 34 countries in the men’s and women’s events, with a total of 40 countries in both events.

The men have 15 of the top 50 in the world, with the lowest-ranked player at No. 321 (Gavin Kyle Green of Malaysia). The women have 24 of the top 50 in the world, with the lowest-ranked player at No. 446 (Cathryn Bristow of New Zealand).

“It’s certainly disappointing that we’ve had so many withdrawals on the men’s side, and wonderful that all of the women have been very supportive,” Dawson said. “What I’m hoping is that when we come to play in Tokyo in 2020 that the top players do support Olympic golf. … It’s the biggest grow-the-game opportunity available, and we need grow-the-game opportunities.

“And I can’t think of a better way for players to give back to the game, frankly, than to support Olympic golf.”