Dustin Johnson was gutted to have withdrawn from the Masters
Johnson suffered a back injury after slipping in his rented home on Wednesday night but arrived at the course an hour before his scheduled tee-time to warm up as normal.
However, after walking up to the first tee, he returned to the clubhouse to confirm his withdrawal officially.
"Worst part about it is in two to three days I'll be just fine," Johnson said.
Masters 2017: Dustin Johnson withdraws from tournament
Thu, April 6, 2017
Click to reveal the first snaps as Dustin Johnson withdraws from the Masters 2017
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Click for the first snaps as Dustin Johnson withdraws from the Masters 2017
"I could swing maybe 70% which was the maximum and it still hurt.
"The backswing is fine but it was impact and through impact is where it was bad.
"I felt like I wasn't going to be able to compete."
Johnson also revealed that the accident had happened as he was heading outside to move his car when, wearing socks, he slipped on a wooden step.
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"After I got back I went to the gym and I was just hanging out at the house when it started pouring down with rain," Johnson added.
"I was trying to be nice because my son was on the way home so I was going to move the car.
"I had my socks on and I went to go walk down the stairs and I slipped.
"I landed on my elbow and my left lower back.
"The elbow is bruised and swollen but that's fine and it doesn't bother me.
"The lower back though is a problem.
"As soon as it happened, I got my brother down to help me get up and I got ice on it."
Johnson also received treatment from a number of different doctors and was seen taking painkillers on the range to try to ease his discomfort.
However, he was not able to join Bubba Watson and Jimmy Walker in the final group of the day, leaving his two fellow Americans to play a two-ball round Augusta on the opening day of the Masters.