AUGUSTA, Ga. (AP) — Masters favorite Dustin Johnson took a serious fall on a staircase Wednesday and injured his lower back, and his manager said it was uncertain whether the world’s No. 1 golfer would be able to play.

It was a stunning development on an otherwise quiet day at Augusta National, where the course was shut down at 1:30 p.m. because of storms.

The real calamity struck a few hours later.

David Winkle, his manager at Hambric Sports, said Johnson fell on the stairs at the home he is renting in Augusta.

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“He landed very hard on his lower back and is now resting, although quite uncomfortably,” Winkle said in an email. “He has been advised to remain immobile and begin a regiment of anti-inflammatory medication and icing, with the hope of being able to play tomorrow.”

What might help Johnson is that he is in the last group for the opening round, scheduled to tee off at 2:03 p.m. with two-time Masters champion Bubba Watson and PGA champion Jimmy Walker.

Johnson has had his share of mishaps in a major but not before a major even started.

On Tuesday, Winkle described Johnson as being “in as good a shape as I’ve ever seen him in every aspect of his game and his life.”

Johnson has won three straight tournaments — including a pair of World Golf Championships — heading into the Masters.

Two years ago, Rory McIlroy ruptured ligaments in his ankle a few weeks before he was to defend his title in the 2015 British Open when he was No. 1 in the world.

But this was different.

Johnson was at Augusta National on Wednesday to play nine holes before the first wave of storms moved in. He was a strong favorite to become the first player since Tiger Woods in 2002 to win the Masters at No. 1 in the world.

Winkle said he would not have any further comment until he knew more about Johnson’s condition.

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