Rory McIlroy's decision not to compete at Rio 2016 over concerns about the Zika virus is "surprising and disappointing", says Ireland's Olympic golf team leader Paul McGinley.
World number four McIlroy, 27, said on Wednesday that taking part in the Games was "a risk I am unwilling to take".
McGinley said McIlroy notified him late on Tuesday.
"As an Irishman, I'm disappointed, but it's not about me, it's about representing Ireland," said McGinley.
Earlier this month, four-time major winner McIlroy said his concerns over Zika - a mosquito-borne virus has been linked to brain defects in newborn babies - had eased.
However, in a statement on Wednesday, he said "my health and my family's health comes before everything else".
He added: "Even though the risk of infection from the Zika virus is considered low, it is a risk nonetheless."
Fiji's Vijay Singh and Australia's Marc Leishman have also pulled out of the Games because of Zika.
Change of heart
Former Ryder Cup captain McGinley told RTE that McIlroy had changed his mind about travelling to Rio "in the last 10 days".
"There's been a lot of noise, particularly in golfing circles, regarding the Zika virus. It is surprising and disappointing but understandable.
"With the press coverage going on and the number of doctors who've come out against competing in the Olympics because of Zika, that is a noise that ultimately that led him to this decision."
McGinley added: "It's not something that I as team leader of the Irish golf can get involved in.
"It's not for me to influence him. This is a health concern that he has. He's discussed it with his family and his wife-to-be and came to this conclusion."
McGinley said world number 73 Graeme McDowell is next in line to join Shane Lowry in Ireland's two-man team for the Olympics.
"With Rory, we had a very legitimate chance of gold," said McGinley. "We still have a lot of good players coming behind who could win a medal, hopefully a gold."
BBC golf correspondent Iain Carter:
While McIlroy's concerns over the risk to his and his family's health should be respected, his withdrawal provides worries for the credibility of golf's return to the Games.
With Marc Leishman and Vijay Singh also steering clear because of Zika fears and Adam Scott, Louis Oosthuizen and Charl Schwartzel staying away for scheduling reasons, the list of absentees is growing.
There will now be close attention on world number one Jason Day and Masters champion Danny Willett. Both have expressed Zika concerns.
If golf has a higher proportion of Rio absentees than other sports, questions over whether it should have been readmitted to the Games will grow louder.