World number one Jason Day has withdrawn from the Rio Olympics due to "concerns about the possible transmission of the Zika virus."
The virus has been linked to brain defects in newborn babies, and Day, 28, is in no mood to risk his wife's future pregancies.
Day and his wife, Ellie, had their second child in November, and he has said they want more children.
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"Competing at the Olympics has always been a major goal, but golf cannot take precedence over my family," said Day, who lines up as the tournament favourite at this week's WGC-Bridgestone Invitational.
The Australian, who has won three of his last eight tournaments, joins a growing number of high-profile withdrawals from the Games including Rory McIlroy, Adam Scott, Charl Schwartzel and Louis Oosthuizen - and the list is likely only going to increase.
With Day, Scott and also Marc Leishman out the running for the Australian Olympics team, it means Scott Hend and Marcus Fraser currently occupy the top two spots in the side.