Van Garderen, who was likely to make the team, is concerned that, if he contracted Zika, he could pass it along to his pregnant wife, who is due to give birth in October.

"If Jessica were not pregnant right now, assuming I was selected, I would go," he told Cyclingtips. "But the fact is, she is pregnant. If we were just going to start trying, I'd say we could start trying six months after the Olympics. But when she has a baby in her belly, I don't want to take any chances."

Van Garderen, 27, was a member of the 2012 Olympic team and most likely would have qualified for one of the two spots on the U.S. team for road events. Both riders must compete in the time trial and road race. A veteran of the Tour de France, van Garderen is considered to be a strong time-trial cyclist whose climbing ability would have been valuable on Rio's hilly course.

Kevin Loughery, a spokesman for USA Cycling, confirmed van Garderen's decision for the Associated Press, adding that he is the only athlete who has chosen to withdraw from consideration for the team, which is expected to be announced June 24.