TROON, Scotland (AP) -- Jordan Spieth said pulling out of the Olympics was the hardest decision he's ever made, and that it likely will haunt him as he's watching golfers compete for a gold medal in Rio de Janeiro for the first time in 112 years.
Spieth cited "health concerns" as his reason for withdrawing, though he said the Zika virus was only part of it. Asked what kept him out of the Olympics, the 22-year-old Texan would only say that it was personal and anyone in his shoes would have made the same choice.
"Why was it so hard? Because I'm a huge believer in Olympic golf," Spieth said Tuesday during a news conference that touched only briefly on his bid for the third leg of the career Grand Slam at the British Open.
"This year I just had to try and weigh a risk that doesn't present itself every year," he said. "And just at the time that I had to make the decision, I just felt this was the right move for me. Not everybody's going to understand. Nobody's going to understand what it's like in my shoes. ... Mine came down to just a very personal decision that, again, I don't expect anybody to understand, but trust that I believe I'm making the right decision for myself, for my future and for those around me."
Spieth's stock has risen sharply in the last year after he won the Masters and U.S. Open and made a spirited run at the Grand Slam. With 18 other players having withdrawn, he was looked upon as someone whose commitment might ease the backlash against golf for its perceived indifference about the sport returning to the Olympics.
That didn't stop him from following his instincts.
Spieth said he didn't make up his mind until Monday morning, and the decision was his alone.
"Everybody's entitled to their own opinion," Spieth said. "I'm not worrying about anybody else except myself, and again, I don't expect people to fully understand it. They don't know what I know about myself and my future and my goals. Therefore, there's nothing I can do about it except go on and try to again focus on this week."
Spieth's decision means none of the top four in the world ranking - they have won six of the last eight majors - will be in Rio when golf is part of the Olympic program for the first time since St. Louis in 1904.
Jason Day, Dustin Johnson and Rory McIlroy previously pulled out, all citing Zika and their plans to start a family or have more children. The mosquito-borne Zika virus has been linked to severe birth defects and possible neurological disorders in adults. International Golf Federation President Peter Dawson said Monday he thought there was an overreaction to Zika and that none of the workers on the new golf course have been affected.
Spieth is staying with Rickie Fowler this week in Troon, and he said he was standing next to him when Fowler tweeted Sunday night that he would be playing. 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.
"He said, 'No worries. I know you had to make it just for you. You're just going to be jealous when I get that gold,'" Spieth said. "That's what he said. So that's how it went."
Either way, Spieth said he would be watching.
He is the defending champion at the John Deere Classic, which was moved to the week of the Olympics when the PGA Tour adjusted its schedule for the Rio Games. Even though he's out of the Olympics, Spieth said he won't go to the John Deere.
"I don't think it would be an appropriate move to play that week, so I will not be playing that week," he said. "I don't think it would be appropriate given our decision on the Olympics. ... We've won two out of the last three years. So I will be going back there, I just don't think it's appropriate this year."
Spieth joked after an introduction to his close call at St. Andrews last year that it would be the easiest question he received. And when it was over, as he pushed back from the table, he said quietly with a smile, "Do we have a tournament this week?"
He was ready to move on from Olympics to a claret jug. But even Spieth knows that won't happen. He said he would carry the decision with him through the Olympics and for a while.
"It will loom over me throughout the Olympic games, for sure," he said. "I will be, I'm sure, at times pretty upset that I'm not down there. I thought about all this ahead of time. When I watch the opening ceremonies, that's going to be a big bummer. Then when I watch these guys competing on the golf course. I'll be texting with Rickie, obviously, throughout as a good friend of mine. I thought about all of this ahead of time and still made the decision I did because it was the right move for me."