Aaron Barrett is attempting a major comeback after what likely should have been a career-ending injury. (John McDonnell/The Washington Post)

WEST PALM BEACH, Fla. — Aaron Barrett is already a miracle.

He’s not supposed to be here, at Washington Nationals spring training, trying to make the team that once gave him his first shot in the major leagues. He’s not supposed to have a chance, pitching alongside all of these guys with smaller scars, or no scars, or medical histories that don’t make doctors stare. And he’s not supposed to be throwing that baseball — definitely not — because there was that one time, the time witnesses will never forget, the time Barrett will never forget, when he released a pitch and … we’ll get to that later.

But the 31-year-old reliever is here, back on the mound, with a right arm full of fastballs and sliders and hope. It’s only because he relearned to trust the same arm that so badly failed him. Otherwise, he’d have no chance at all.

“Sometimes I need to take a step back and tell myself, ‘Dude, you’re doing it,’ ” Barrett said one recent morning, his eyes filling with tears as he squinted toward the table in front of him. “It makes me emotional just thinking about it.”

He let a few beats of silence pass with a slight breeze.

“I don’t know; it’s crazy.”

***

Barrett has told this story, and he will tell it again, over and over, to his kids and grandkids and whoever else wants to hear.

It was July 2016 in Viera, Fla., on a back field at the Nationals’ old spring training site. Barrett was like any other rehabbing major league reliever. He was drafted by Washington in 2010 and was a key part of their bullpen four years later, pumping mid-90s heat with a biting slider. Then his arm felt sore in 2015 after he appeared in 30 of the Nationals’ first 60 games. Then he couldn’t feel his fingers, an MRI revealed damage to his ulnar collateral ligament, and he underwent Tommy John surgery.

Then, recovering in Viera less than a year later, throwing a simulated game, his arm snapped. Just like that. Pitcher Ronald Pena described the sound as a “full-on gunshot.” Paul Menhart, the Nationals’ minor league pitching coordinator, likened it to a piece of plywood being kicked in. It was a broken humerus that made him leap around the mound, crying and screaming, immediately asking, “Why me?”

Mat Latos, waiting to throw after Barrett, vomited in the dugout. Pena, waiting to throw after Latos, was afraid to pick up a ball. A video of the injury was sent to then-Nationals Manager Dusty Baker in Washington, and it was soon stored on a locked hard drive so no one would ever watch it again.

“I’ll never forget that sound,” Pena said this February. “Not for the rest of my life.”

James Andrews, the renowned orthopedic surgeon, had never seen damage like this. It looked as though Barrett had been hit by a car, and it required Andrews to perform a surgery he never had before. It was all an experiment, and it was supposed to take two hours; Andrews operated on Barrett for six.

The goal wasn’t to get Barrett back to a big league mound. It was for him to have a functional right arm.

“When the surgery was finished, the doctors and medical staff just wanted my arm to work again, to be able to hold any weight, be lifted up,” Barrett said. “They weren’t thinking about it throwing a baseball.”

And neither, as it turned out, was his brain.

***

When Barrett threw again for the first time, in the December following surgery, he was initially surprised by how his arm felt.

He had no idea where his arm was during his motion — whether it was behind his head, straying outside of his body or coming over the top — but there was no pain. At least not in the moment. Not until it started throbbing that night.

This was his brain’s way of sending negative signals, Barrett later learned, because his last throw led to such a traumatic experience. His brain couldn’t forget that. He would have to train it to. So Barrett sought help from Seth Oberst, a physical therapist in metro Atlanta who helps people integrate their body and mind. That’s where the path to renewed trust began.

“Nothing about throwing a baseball as hard as you can is natural, so you have to have a ton of trust in your body and arm,” Menhart said. “I cannot imagine what Aaron had to go through, from a mental standpoint, to do it again. I can’t imagine what it was like to start over after what happened.”

During his first meeting with Oberst, Barrett had to imagine an invisible, weighted baseball on the back of his right hand. Then he had to visualize slowly moving that baseball up his arm, and try to feel each bump as the leather and seams moved from his wrist to his elbow and all the way up to his shoulder. It took Barrett three sessions to get comfortable with the exercise, and that’s when his brain and arm started to reconnect.

Oberst also taught Barrett deep breathing exercises and, more than anything, they talked for close to three months. Barrett had thrown a baseball since he was 4 years old and never thought much about how odd it is. The body is not built for the arm speed needed for a 95-mph fastball, the torque needed to spin a slider, the stamina needed to repeat a violent motion over and over and over again. Barrett had to trust that his elbow could be what it was before Tommy John surgery and, really, before it broke altogether. He had to believe in a process no one had ever gone through, a rehabilitation plan being written on the fly, a promise he made to himself and his family and everyone who had invested in his career.

By spring 2017, when the Nationals re-signed him to a two-year minor league contract, he was ready to let the past be exactly that.

“My arm isn’t going anywhere, my arm is bionic, and it’s not going anywhere,” said Barrett, hinting at all the screws keeping his elbow intact. “Hopefully I get to play for another 10 years with the arm that I have. It’s going to be fine. I know that 100 percent. I am fully confident that nothing is going to happen.”

This time he looked down at the table and knocked on wood.

***

This long and winding comeback is dotted with milestones, stacking up like a pile of old magazines, from the moment Barrett’s arm snapped to right now.

There was his first bullpen session after his surgery, around this time last spring, when Nationals Manager Dave Martinez and pitching coach Derek Lilliquist made a point to watch. There was his first minor league appearance this past summer with the Auburn Doubledays, a Class A short-season team in the New York-Penn League. There was his first bullpen this spring, at the start of his first major league camp since 2015, when Menhart wrapped him in a bear hug once it finished.

Every step brings relief and reflection and a realization that this may not be it. Barrett wants to get back to the majors and stay there. He has a 16-month-old daughter, Kollyns, and can’t stand the thought of her Googling his name, years in the future, and seeing that he gave up. It’s part of the reason he won’t, not until he is on the mound that helped build his name, at the center of Nationals Park, for a team he believes can win a World Series.

He says he will write a book one day and that the ending hasn’t happened yet. Nationals General Manager Mike Rizzo, who has stuck with Barrett when others wouldn’t, thinks it could be a movie. There is a photo in the main hallway of Washington’s spring training complex with Barrett, back to the camera, celebrating a win with his teammates in 2014. It’s a reminder that he’s not quite like all the other hopeful, nonroster invitees battling through camp. It’s a reminder that he’s been there.

“His arm exploded, and he is still going out there every day,” Nationals first baseman Ryan Zimmerman said. “That’s incredible to me. Everyone here wants him to get back. It’s where he belongs.”

But Barrett was mixed in with those hopefuls Feb. 27, laboring through the ninth inning in his second appearance of the spring. He probably will head to the minors once the season starts, either to Class AAA Fresno or Class AA Harrisburg, and look to earn a call-up from there. Now he threw in a near-empty park in West Palm Beach, holding an eight-run lead against the Houston Astros, with the daylight fading and Rizzo watching from the first row by the dugout.

Barrett induced a soft flyball that should have ended his day but, instead, splashed into the center field grass. He was tagged for two runs and shook his head when he walked off the field. But that was just fine. There had been enough miracles for one day.

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