(Reuters) - World number one Jason Day and Ireland's Shane Lowry on Tuesday withdrew from August's Rio de Janeiro Olympic Games, citing fears over the Zika virus. Golf is returning to the Olympics for the first time since 1904, but a number of big names, including four-times major champion Rory McIlroy, Fiji's Vijay Singh and Charl Schwartzel of South Africa, have also pulled out due to Zika concerns. More...