Dustin Johnson has been forced to withdraw from the Masters due to a back injury.
Johnson was clearly in pain as he warmed up on the range after paying a visit to the physical therapist upon his arrival at Augusta National, and he headed to the first tee without doing any work on his short game.
According to the PGA Tour, the world No 1 vowed to "give it a try", but after arriving at the first tee, he then headed to the clubhouse before announcing he was pulling out.
His caddie, brother Austin, had to tee his ball up for him as he hit a few cautious drivers under the watchful eye of coach Butch Harmon, and he did not seem capable of hitting at full power.
Johnson emerged as a shock injury doubt ahead of his first major as world No 1 when he took a tumble on a staircase at his rented house in Augusta on Wednesday afternoon.
The American's manager revealed he "landed hard" on his back in the freak accident and was advised to stay immobile while being treated with painkillers to ease the discomfort.
Johnson, who has won his last three tournaments to extend his lead at the top of the world rankings, was apparently wearing socks and not shoes and was running down the polished wooden staircase when he slipped backwards.
The incident happened shortly after the 32-year-old reigning US Open champion returned to the house with his family after play was suspended for the day due to severe storms in the region, which forced the cancellation of the Par 3 contest.
His manager David Winkle released a statement which read: "At roughly 3:00pm (Wednesday), Dustin took a serious fall on a staircase in his Augusta rental home.
"He landed very hard on his lower back and is now resting, although quite uncomfortably. He has been advised to remain immobile and begin a regimen of anti-inflammatory medication and icing, with the hope of being able to play."