The young American led overnight after an opening 67, but he struggled on day two and was two over for his round when he arrived at the par-three fourth – his 13th of the day.
Spieth’s well-struck long-iron from the tee took a hard bounce and finished in light rough at the rear of the green, leaving him a routine chip to save his par.
But as Spieth made his way to the green a marshal apparently stepped on his ball, although he failed to notify the player of his mishap.
Spieth was informed of the incident by members of the gallery, and he lost his focus as he left his pitch four feet short and then missed the putt for par.
He managed to haul himself back into contention with birdies at his last two holes salvaging a one-over 72, leaving him just two shots off the lead heading into the weekend, but the events at the fourth left a sour taste.
“I hit a really good shot right over the green and I knew it would be a basic pitch back on or a tap-in birdie,” he said. “I guess one of the officials kicked my ball or stepped on it and it moved.
“I didn’t know and some of the crowd told me that he had done that and that’s the third time it has happened this year, and each time it has cost me a shot – all three times.
“It is really amazing because the ball was 10 feet off the green and I don’t see how you don’t know where the golf balls are. I went from a chance at making a two there to making a four, and I was not happy going to the next hole.”
Spieth admitted he had struggled to find his rhythm from the start, but he was pleased to grab two late birdies to give him some momentum heading into Saturday’s third round.
“It was a big-time struggle,” Spieth added. “I wasn’t hitting it well and, if I wasn’t putting well, I might have shot 45 on that front nine.
“Just didn’t find the ball-striking until the last few holes and was very fortunate to grab a couple of birdies on eight and nine, two really difficult holes.”