Dustin Johnson is a shock injury doubt for the Masters after suffering a "serious fall" down a staircase a day before the opening round.
The American's manager revealed he "landed hard" on his back in the freak accident at the house he is renting in Augusta and is in some discomfort, although he is still hoping to play.
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.
Johnson still remains hopeful of featuring in his first major as world No 1, and doctors have put him on a course of anti-inflammatory medication to ease the pain.
He was due to attend the annual Golf Writers Association of America awards dinner on Wednesday evening, but he has been advised to remain at home and stay immobile.
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."
Johnson has maximum time to recover as he is scheduled to tee off in the final group of the first round at 2:03pm local time (7:03pm BST) along with PGA champion Jimmy Walker and two-time Masters winner Bubba Watson.
The US Open champion is no stranger to suffering injuries ahead of the Masters, having had to pull out in 2012 after he strained his back while lifting a jet ski.