Spieth's barb at Greller came on the par-4 eighth hole of the opening round. Spieth played it safe and used a 4-iron, but when Spieth and Greller reached the end of the fairway, they learned the shot rolled about 45 yards through the fairway and into the water.
Spieth dropped a ball on the opposite side of the fairway for his third shot on the hole. Needing to hit onto a small green that was significantly sloped to the front, he shot over the green and landed in the deep rough.
As he walked to the eighth green, Spieth said, "Two perfect shots there, Michael. You got me one in the water and one over the green."
Spieth's comments were quickly criticized on social media for throwing his caddie into the fire. After the round, the golfer said he was "frustrated" that they didn't come up with the correct number on his third shot and defended his intentions.
"We were talking about potentially one less [club] and I said, 'But isn't it playing about 60 with a fade?' And then he said, 'Yes,'" Spieth told reporters. "So we both agreed on that. It was clearly a 4-iron off the tee. At the same time, when you hit a couple of shots exactly where you want to, and the first one is in the water and the next one is dead over the green, I'm going to be frustrated that as a team we didn't figure out how to make sure that didn't happen.
"Yeah, I may have looked like the bad guy there, but my intentions were that we should be in play if the ball is hit solidly, and I was out of play on both shots."