Dustin Johnson fell down the stairs on Wednesday, sustaining a back injury just one day before the start of the Masters.
The world's top golfer, Johnson had won three consecutive tournaments and was the favorite to capture this year's green jacket at Augusta National.
Now it's unclear if he will even play.
On Thursday, Johnson's trainer told Golf Digest that Johnson has only recently gained mobility.
"We got him to the point where he got mobility," trainer Joey Diovisalvi said. "He was up and moving around and definitely going in the right direction. He was very much in an under control point going to bed last night."
"He was walking around, a lot more mobility, took a couple of practice swings slowly without a club."
ESPN's Tom Rinaldi, meanwhile, reported early Thursday that Johnson was in "significant pain" and had a hard time finding a position to rest comfortably.
According to Golf Digest, the pain Johnson has is on the lower left side of his back, below his ribs.
Rinaldi noted that nobody will know whether or not Johnson is ok until he makes an appearance at the golf course and starts to swing a golf club. However, the simple fact that we now know Johnson only recently "gained mobility" certainly suggests a more serious injury than many expected when news of his fall was first reported. A four-day golf tournament is incredibly taxing on the body, and on the back in particular. If this injury doesn't keep Johnson out of the tournament entirely, at the very least it no longer makes him the favorite to win.
Johnson does at least seem to be taking the injury as well as he can.
"Obviously disappointed that he fell," Diovisalvi told Golf Digest. "He told us, 'I'm going to do everything I can to go out and play tomorrow.' That basically is his attitude. He was playing with Tatum. Life sometimes happens. He’s not angry or upset, I'd say more discouraged."
If there's any consolation for Johnson, it's that his Thursday tee time isn't until 2:03 p.m., which should give him a few extra hours to recover.