AUGUSTA, Ga. — This is the day to make fun of Dustin Johnson, right?

This is the time to point out that some guys lose the Masters because of frayed nerves, a bad bounce, an unfortunate read of the greens. Dustin Johnson? He’s the only man alive who could lose the Masters because he was wearing socks instead of shoes on three wooden steps.

Really, the only surprising development here is that Johnson didn’t slip on a banana peel discarded by his brother and caddie, Austin, another easy target on tour. The Johnsons have long been cast in golf circles as the opposite of rocket scientists, whatever that is, and they’ve never seemed to take great offense to the labels.

But this is no laughing matter for the sport, for Augusta National or for anyone who cares about great athletes trying to do great things. For starters, Johnson proved his mental toughness last year at Oakmont, where he overcame a grizzly bear of a golf course and an absurd ruling — even by USGA standards — to win the U.S. Open. When Johnson was done hitting the approach shot of his dreams on the 72nd hole, rendering the rules fiasco moot, Jack Nicklaus shook his hand and said, “I thought what you did with all that crap they threw at you was pretty good.”

It was a long par 5 that was better than pretty good. It was the arrival of the best athlete this sport has ever seen.

The best athlete had grown into the best golfer, and that’s why Johnson’s decision Thursday to pull out of the Masters a minute or two before his 2:03 p.m. tee time is best described by DJ in perfectly simple DJ fashion.

“It sucks really bad,” he said.

Sure does.

He wasn’t just golf’s reigning freak of nature anymore, half-LeBron and half-Gronk. He wasn’t just the explosive, 6-foot-4 long baller with a condor’s wingspan who happens to be engaged to the famously beautiful and beautifully famous Paulina Gretzky.

Johnson arrived at Augusta National as the world’s top-ranked, and hottest, player. He had won three consecutive tournaments and, at 32, was very much in the sweet spot of his prime. With his brute power and ever-improving short game, he had a chance to do what Tiger Woods did here 20 years ago and, you know, pull a Secretariat on field.

But then DJ left the gym Wednesday and headed to his rented house, where he waited for his son Tatum to return from day care. It was pouring outside, and Johnson decided to move his car to clear room in the driveway. He didn’t put on shoes because, well, it’s hard to imagine Johnson ever wearing shoes when he doesn’t need to.

Only he needed to on those bare wooden stairs. Johnson’s feet went out from underneath him, and he crash-landed on his elbow and left lower back.

“It actually would’ve been better if it would’ve been a full set of stairs,” Johnson explained, “because I would’ve just slid down it. But it was only three, so I kind of landed on the bottom.”

DJ called for Austin to help him get up and then lie down, iced his aching back and waited for the doctor to arrive. Johnson rotated ice and heat through a restless night, took more treatment through the morning, and then he made his way to Augusta National, where he tried to work through the pain on the practice range. As Butch Harmon, his coach, looked on, Johnson looked about as stiff and inflexible as Woods did in February in Dubai. DJ mimicked his hip turn on the range, wincing as he did it. It seemed he was telling his coach he couldn’t get through the ball.

With his tee time closing fast, Johnson suddenly appeared at the putting green, raising the expectation that he would answer the bell. First bad sign: Someone asked DJ how he was feeling, and DJ responded, “Could be better.” Second bad sign: Johnson consulted with a small circle of advisers, and they all looked as if they’d just swallowed some sour milk. Third bad sign: Security guards and green jackets started clearing Johnson a path to the clubhouse, not the first tee.

“Dustin,” a fan said on his trudge off the course, “I’m real sorry, man.”

Johnson nodded at the man and disappeared into the locker room. Soon enough he returned to answer some questions, to explain how someone can miss the cut on Thursday afternoon.

Johnson said his left lower back was the problem, not his elbow, and that it was too tight for him to even try playing a few holes. He said his backswing was fine, but that “every time down, right at impact, it would just catch.”

As much as hated the very idea of it, Johnson had to surrender to the inevitable. “I just don’t feel like there’s any chance of me even competing,” he said.

The decision sucked the life out of the windblown start to this tournament. Johnson had triumphed last year over all of his major championship demons from Chambers Bay, to St. Andrews, to Whistling Straits and beyond. The Masters was his to win, or lose. Everyone from Jordan Spieth to Rory McIlroy knew it.

And then Johnson walked away. If a heavy favorite had ever made a similar last-minute exit from major championship golf, nobody could remember it. In 1962, days before a hometown U.S. Open he desperately wanted to win, Arnold Palmer cut his hand removing luggage from the trunk of his car. It didn’t stop him from playing Oakmont. But that cut and the stitches it required might have ultimately stopped him from beating a rookie named Jack Nicklaus.

Fifty-four years later at Oakmont, after Dustin Johnson won his first major title, his brother said DJ had never been unnerved on a golf course, not even by the USGA suits who harassed him during his final round. “I’ve never seen him pissed off,” Austin said.

Johnson was pissed off Thursday at Augusta.

“It feels like probably in two days I’ll be fine,” he said. “If it happened on Monday, I don’t think we’d have any issues. But it happened Wednesday afternoon.”

In another time and place, this freak accident might’ve been good for a belly laugh or two at DJ’s expense. But a great, tough athlete had to bail on golf’s Super Bowl in the prime of his career, and let’s face it: There’s nothing even remotely funny about that.