Johnson came to the Masters as a red-hot favourite having finished fourth last year and broken his major duck months later, winning the US Open.
The 32-year-old has since claimed the world No1 spot but suffered a freak back injury on Wednesday night in the home his family have been renting near the course.
And he was forced to pull out minutes before he was due to start his challenge.
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 want to play," Johnson said.
"I just can't swing.
"Worst part about it is in two to three days I'll be just fine."
Johnson had been playing with his two-year-old son Tatum on Wednesday when he slipped on a wooden step and landed hard on his elbows and lower back.
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Dustin Johnson warmed up but walked off the first tee at Augusta
He was quickly attended to by PGA medics and his own trainer and was given anti-inflammatories and a regime of icing in an effort to get him ready for a 7.03pm BST tee-time on Thursday.
Johnson arrived at the course as normal, heading to the range for a warm-up with coach Butch Harmon an hour before his round as normal.
And when he left the range, Harmon was under the impression he would play the round but warned him not to push the limits of possibility.
Dustin Johnson practiced with Brooks Koepka and was in good spirits before his injury
“He was going to see if he could play," Harmon said.
"He didn’t want to waste his time and embarrass himself.
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"Just looks like he couldn’t go.
"I said to him that if your body won't allow you to hit a certain type of shot then I think you're wasting your time."
And Johnson seems to have thought he was not able to hit some shots as he walked off the first tee without hitting a shot, leaving Watson and Walker to play as a two-ball in the final group of the day.
The odds on him winning had been drifiting since Wednesday night with Jordan Spieth going off as a 13/2 favourite.
Rory McIlroy is also well-fancied at 7/1 while Jason Day at 15/1 will shorten now that Johnson has been ruled out.