Dustin Johnson has become the seventh top golfer to pull out of the Olympics because of concerns over the Zika virus.
The number two in the world, who won the World Golf Championship last week, is the eighth golfer to pull out of the tournament, which is due to start on August 5.
Of the world’s top four golfers only Jordan Speith is now due to make an appearance at Rio, which will mark golf’s return to the Olympics after a 112-year absence.
Patrick Reed, who said earlier this week at the Scottish Open he wants to play in the Olympics, would replace Johnson.
The United States is allowed four players, the most of any country in golf, because they are in the top 15 in the world.
‘This was not an easy decision for me,’ Johnson said in a statement released by his management company. ‘But my concerns about the Zika virus cannot be ignored.’
Johnson said he and his fiancée, Paulina Gretzky, plan to have more children. They have an 18-month-old son, Tatum.
‘I feel it would be irresponsible to put myself, her or our family at risk,’ Johnson said. ‘I believe I am making the right decision for me and most importantly, my family.
‘While I am sure some will be critical of my decision, my hope is that most will understand and support it.’
The decision follows a meeting at the Bridgestone Invitational with USA Golf in which the leading four Americans were briefed on Zika and security concerns.
Johnson had called it a productive meeting and that he was planning to play, though he still wanted a few more answers.
Of the top four Americans, only two-time Masters champion Bubba Watson said he is going. Golf was last an Olympic sport in 1904 in St. Louis.
Nine of the 13 players who have withdrawn are among the top 30 in the world — Day, Johnson, McIlroy, Adam Scott, Branden Grace, Louis Oosthuizen, Hideki Matsuyama and Shane Lowry.