With golf making its first appearance in the 2016 Olympics in 112 years, and a vote coming in 2017 to decide whether it stays or not, the 2016 event in Rio is off to a weak start.

Some of the world’s best players have little interest competing in the 2016 Olympics, and others are concerned about their health and the health of their unborn children, CBSsports reported.

The Zika virus is why South African Charl Schwartzel is skipping the Olympics, according to an AP report in PilotOnline.

Speaking for the first time about his decision in late April to pull out, Schwartzel said he and his wife want to have more children and the risk of Zika is too great.

“If I didn’t want to have children, or if I was single, I’d play,” Schwartzel said Friday. “It’s as simple as that.”

The former Masters champion told golf officials in late April that he would not be playing golf in the 2016 Olympics, according to BusinessInsider. Schwartzel said Friday that he loves the Olympics and would play if it was anywhere but Rio because of the Zika virus.

Schwartzel and Marc Leishman of Australia are the only golfers who have said Zika is why they won’t play.

The world’s No. 1 golfer Jason Day has been a strong proponent of golf’s return to the Olympics after a 112-year absence. A month ago he said it would be a huge honor to win a gold medal for Australia. With two childre, and plans for more, he began to back off on Friday.

Day said he got worried when when he heard about Detroit Tigers pitcher Francisco Rodriguez, who contracted the virus in Venezuela during the off season and was sick for nearly two months. Rodriguez told ESPN.com he wouldn’t blame athletes for skipping the Olympics, especially if they might have more children:

Rodriguez, a 34-year-old native of Caracas, Venezuela, contracted the virus this past offseason and learned just how serious the illness can be. He was laid up for two weeks with severe bodyaches, joint pain, headaches and a myriad of other symptoms. Considering the effects of the illness are even more devastating for women, especially pregnant women, he advised any athletes contemplating participating in the Olympics to educate themselves and their family members.

A group of 150 health professionals around the world called for the 2016 Olympics to be postponed.

The World Health Organization said the mosquito-bourne Zika virus can cause microcephaly in infants and other developmental issues, and is a public health emergency of international concern. But WHO stopped short of calling for the 2016 Olympics to be cancelled or moved, saying it “will not significantly alter the international spread of Zika virus,” ESPN reported.

Brazil has been hit hardest of the 60 countries that have reported Zika outbreaks.

Louis Oosthuizen of South Africa and Vijay Singh of Fiji said they are not playing, though they did not blame Zika.

“I don’t think it’s an Olympic issue. I don’t think it’s a Rio issue,” Day said. “I just think it’s a medical issue attached to what happens if I go there, get it and bring it back. They don’t know. You don’t know how long it’s going to last in your body. So I’m a little wary about it.

“I’ve just got to make a smart, educated decision whether to go or not.”

Schwartzel and his wife have a 2-year-old daughter and plan to have more children, AP reported. The South African said he expects more golfers to think hard about going, and wouldn’t be surprised if more pulled out.

“You can hear the guys mumbling about it. It’s definitely stuck in their heads,” Schwartzel told AP. “I would go so far as to say anyone going is not comfortable going. I think it’s a worry for them. It’s a choice.”

The International Golf Federation is giving Zika-related information to the tours and player liaisons, and made available its doctor last month at the PGA Tour for anyone with questions.

“I’m not saying there’s bias,” Day told AP. “I’m just saying we need independent advice. I think there are a lot of guys on the fence about it because they don’t want to put themselves in harm’s way.”