Jordan Spieth being the latest. So why is this happening?
Perhaps it may be a little unfair to characterize these players (and you can see the full list here) as "pulling out" of the Olympics because for a good chunk of them, they were players that had qualified but may not have committed before changing their mind. So if you want to quibble with the language, go right ahead.
It seems as if the most common reasons as to why players are pulling out of the Rio Games seem to be the Zika virus and the schedule. Both of which make sense. Even as the games will be taking place during the winter in Brazil, meaning that risks of getting Zika by way of mosquitoes carrying the virus are not as high as they would be during the summer, it is still a very legitimate medical concern. And as for the schedule, you can't find much fault with that logic considering that the next nine weeks include the final two majors of the year, a World Golf Championship event and then the FedExCup commences just one week after the Rio tournament.
But it is also important to note that as of press time, only one player on the women's side has withdrawn from the games. So since those claims are not exclusive to the men, could there be more at play here?
Considering that this is the first Olympics with golf in such a long time, it really isn't a big deal for these players when compared to the majors, to the FedExCup and the Ryder Cup which is the established top tournament for international competition (and don't forget about the Presidents Cup either). I bet for the majority of the players on tour, this is little more than just another tournament to them.
Of course, one could have also said the same thing for when tennis returned as a full medal sport at the 1988 Summer Olympics in Seoul and it was able to catch on as a big deal for the sport's elite, and especially so when they started award ATP and WTP points for it last decade (which they stopped for 2016). But one could also spin that in because there is virtually no interest in tennis outside of the Grand Slam tournaments and thus the Olympics were able to step right in and be a big deal but again with golf, there is a lot more competition there.
So it definitely is disappointing that only four of the top ten ranked players in the world and eight of the top 15 are participating with the highest ranked player being the great Bubba Watson (ranked fifth). It should still be a fun tournament, especially if the Gil Hanse-designed course delivers as hoped, and the field is not terrible but if golf is going to be more than a periphery Olympic sport, the stars are going to have to come out.