Golf 's return to the Olympics for the first time in 112 years has been hit by a host of the world's leading male players withdrawing en masse.
Jason Day, Dustin Johnson and Rory McIlroy previously pulled out, all citing Zika and their plans to start a family or have more children.
McIlroy, who rates the four Majors as more important, also questioned whether golf was doing enough to justify its Olympic status in terms of drug-testing.
"This was something I very much struggled with", Spieth said Tuesday at Royal Troon, home to the 145th British Open that begins Thursday. The Olympics can and should be special but given the IOC's irresponsible decision to put the Games in Rio with all of its rampant problems it's not surprising many top players are taking a pass.
"I didn't get into golf to try and grow the game. I bounced back and forth with, and ultimately a decision had to be made yesterday, and so I made it".
"I won't watch golf at Olympics", he says.
Asked what would top his viewing schedule, he added: "Probably the events like track and field, swimming, diving - the stuff that matters". Spieth had planned to room with Fowler in Rio, and he said he texted Fowler after informing the IGF that he wasn't going to play.
"No offence to the Olympics, but I'd rather be on the Ryder Cup team", he said.
Jordan Spieth calls skipping the Olympics "probably the hardest decision I've had to make in my life".
Willett was sympathetic to those who have chosen not to go while emphasising how the appeal of the Olympics was just too great for him to resist.
Spieth faced a deadline for his decision because the competitors from various countries were decided on Monday. "I don't think it would be appropriate given our decision on the Olympics".
Spieth nearly notched up three in a row at last year's Open Championship at St. Andrews, but fell short of a play-off place.
But McIlroy has made no secret of his contempt for golf as an Olympic sport.
"It's the Open Championship, you know coming in here that you're going to have to battle the elements somewhat", said McIlroy.
"Obviously with golf being an outdoor sport played around the water out there, five, six hours out on the golf course, seven days a week, you are probably at a higher risk than most other athletes in most other sports who are in much more of a contained environment".
"Thankfully after getting off to a pretty slow start I was able to make a run of birdies there and finished the front nine pretty well and then as you saw on the back nine, it's very hard today".
"Look, I get where different people come from and different people have different opinions". Spieth, who won last year's U.S. Open and Masters tournaments, is one of the athletic brand's biggest athletes of the moment.