Many of world's top players won't go to Olympics

Top-ranked Jason Day, Rory McIlroy and Adam Scott lead a host of men's golf stars who have withdrawn from the Rio Olympics - an exodus that could jeopardize the sport's return to the Games lineup after 112 years.

The mosquito-borne Zika virus, which can cause birth defects and severe illness, is mentioned by many - including Australia's Day, Northern Ireland's McIlroy and Japan's 17th-ranked Hideki Matsuyama - as one of the growing list of Rio woes ahead of next month's Olympics.