Patrick Reed, the US Ryder Cup player, is the latest top golfer to waver in his commitment to the Olympic Games.
Concern about the Zika virus has led to many of the game's stars withdrawing from Rio.
Reed was previously unequivocal about representing his country, saying on Wednesday that if the call came then he would definitely play.
After Saturday's Scottish Open third round he said: "We have to weigh up our options and make the right decision."
World number two Dustin Johnson is the latest big name to opt out, announcing that he would not put himself and his family at risk to the Zika virus.
That meant Reed, 25, was immediately promoted to America's four-man team as the US Open champion's replacement.
Reed has now expressed newfound doubt about his own participation.
The Texan, America's best performer at the Ryder Cup at Gleneagles in 2014, had previously said: "Any time I can wear the Stars and Stripes, I do it. If I get the call tomorrow, I'll be on the flight. It doesn't matter to me where it is, when it is. If I can play for my country, I'm going to play."
'Dreamed of a gold medal'
After his third round 67 at Castle Stuart, and having been woken in the middle of the night with word of Johnson's withdrawal, Reed was a little more circumspect about his commitment.
"My phone was blowing up at 3.30am, 4am," he said. "I didn't know what was going on. When the phone starts blowing up at that time I'm sitting there thinking 'All right, what's going on at home? Did something happen?'
"The news was that DJ withdrew and everyone has to respect that decision. We have to weigh our options and make the right decision. As far as I know, I'm going to go and play, but at the end of the day I need to go and talk to the whole family and talk to my team and make sure it's the right decision."
On Wednesday, Reid said he'd already spoken to his wife, Justine, a registered nurse, and that the decision had been made. If he was given the chance to play, he would.
"I've always dreamed about being able to play for a gold medal," he had stressed.
However, Reed pointed out on Saturday that there are certain things he still has to consider. "All the factors everyone else is (weighing up). You know, security, Zika, everything. Hopefully I can play."
Golf will return to the Olympics after a 112-year absence but Johnson's decision has come as another terrible blow to the credibility of the event in Rio.
Johnson has an 18-month son with his fiancée, Paulina Gretzky, and plans to have more children soon.
"I feel it would be irresponsible to put myself, her (his fiancée), or our family at risk," Johnson said in his statement. "I believe I am making the right decision for me and most important for my family."
Johnson joined a growing list of golf's players finest to pull out, among them Jason Day, the world number one, Rory McIlroy, world number three and Adam Scott, world number eight. The American became the sixth player from the game's top-20 to opt out of Rio.
Earlier in the week, Colin Montgomerie was critical of those players who have withdrawn from the Olympics, saying that by staying away they are putting in jeopardy the sport's future in the Games.
All Olympic golf teams - four-player squads - must be finalised by Monday.
As it stands, the USA team will be Jordan Spieth, Rickie Fowler, Bubba Watson and Reed. Both Spieth and Fowler have, however, stopped short of fully committing to play.