It was only the second day of full workouts during 2021 Spring Training. Paul Blackburn carried a plate of food from the dining room to his locker inside the A’s clubhouse at Hohokam Stadium and saw there was a missed call on his phone. It was from A’s GM David Forst. 

Anxiety struck. Before he could dig into his breakfast for the day, Blackburn had to return the call. Forst picked up and got straight to the point. The A’s needed to open up a spot on the 40-man roster after signing free agent Mitch Moreland. Blackburn, who was already a player on the bubble, was designated for assignment.

• MLB All-Star Game presented by Mastercard: Tuesday on FOX

The news didn’t exactly blindside Blackburn. He knew where he stood in the organization. Sure, he showed promise with a solid 2017 rookie campaign. But ever since then, injuries and struggles led to a 9.22 ERA with Oakland from 2018-20. Several times over that trying stretch, self-doubt led to him pondering what he might do if this whole baseball thing didn’t work out. Now, that scenario was staring him right in the face.

“I was trying to figure out what was next for me,” Blackburn said of what was going through his mind after the DFA. “There have been times where I pictured myself out of this game and tried to think about what I would do after baseball, just with a lot of the stuff I was dealing with the last few of years.”

• 'At a loss for words': Blackburn earns 1st All-Star selection

This was the moment that altered his career. If you’re wondering how Blackburn’s career went from A’s castaway to gearing up to compete against baseball’s elite players at the 2022 All-Star Game at Dodger Stadium, it was his actions after receiving that wake-up call from Forst on Feb. 23, 2021, that sparked his miraculous turnaround.

Originally scheduled to throw a live batting practice session later that day in A’s camp, Blackburn was instead sent to baseball purgatory. When a player gets "DFA'd,” a seven-day period follows in which they can either get claimed off waivers by another team, outrighted to the Minor Leagues or granted a release from the organization. Those going through this situation usually take at least a few days to clear their mind. But Blackburn was not about to feel sorry for himself.

Instead of taking a break, Blackburn set out on a mission to prove he was a better pitcher than the career numbers had shown to that point. With the A’s Spring Training facility no longer available to him, he called A’s throwing performance coach Casey Upperman, who also runs Rotational Athlete Solutions in North Phoenix.

What Upperman saw that day from the right-hander in that 40-pitch session was unlike anything he’d seen from him before. Blackburn turned anger and frustration from the DFA into fuel and motivation on the mound.

“He threw that day, and that was the best I ever saw him throw up until that point,” Upperman said. “That told me a lot about what was going to happen. We have a lot of big league guys who’ve been DFA’d. I’ve never seen someone come in with the fire that he had.”

Blackburn used that time away from the A’s as an opportunity to rebuild his mentality as a pitcher. There’s a reason why he was a first-round pick by the Cubs in the 2012 MLB Draft. As a standout at Heritage High School in Brentwood, Calif., scouts were enamored with Blackburn’s impressive curveball and superb control of the fastball. Above those aspects of his game, though, was a strong belief system.

That key quality held true for Blackburn in 2017, as he posted a 3.22 ERA in 10 starts as a rookie with the A’s but soon became lost through season-ending forearm surgery in '18 and struggles in the following seasons. That session at Upperman’s training facility was the first step toward regaining his confidence.

Blackburn got through waivers unclaimed and was outrighted to Triple-A Las Vegas on Feb. 27, 2021. Posting solid numbers in the hitter-friendly Pacific Coast League that year, Blackburn’s contract was selected by the A’s on Aug. 18 after an injury to Chris Bassitt opened a slot in the starting rotation.

Blackburn made nine starts for Oakland in the middle of a playoff race. His best outing came in front of a national audience for Sunday Night Baseball, when he tossed five scoreless innings in a win over the Yankees on Aug. 29 at the Coliseum. 

Following that scoreless performance, Blackburn was emotional in his response when asked what it meant to be experiencing success in the Majors again. 

“It’s a lot of fun," Blackburn said. "The last couple of years have been a struggle. Just coming up here and being able to help out is amazing.”

The joy was back for Blackburn, and the success of late 2021 starts bred more confidence. Taking only a week off following the end of the season, Blackburn returned to Arizona to prep for 2022. Upon arrival, Upperman instantly noticed a different presence from Blackburn on the mound. There was an unbreakable belief that his best stuff can compete with any hitter in the league. Even if an opponent got the better of Blackburn on a certain pitch, he was going to keep attacking the next batter. 

“He’s developed an ace mentality,” Upperman said. “He truly believes, every time he takes the mound, he is the best pitcher in the world. That’s not cliché. He really, truly believes that. His mindset changed."

Where did this newfound confidence come from?

“A ton of work,” Upperman said. “That guy is [working out] five days a week the whole offseason. Repetition and seeing it work also built confidence. He had the bumps in the road that he used to his advantage. When he rolled out of this offseason into Spring Training, I knew it was going to be different.”

• Even in defeat, Blackburn flashes All-Star form

In 2022 Spring Training, Blackburn beat out several other pitchers to earn a spot in the Opening Day rotation. Halfway through the season, he’s now held opposing teams to two runs or fewer in 11 of his 18 starts this year, including six scoreless outings. He carries a 3.62 ERA into the All-Star Game, where he could get a chance to showcase a curveball with a -6 run value that trails only Shane McClanahan, Zac Gallen and Justin Verlander for the most productive curveball in the Majors.

On the surface, this achievement shouldn’t come as too much of a surprise given Blackburn’s amateur pedigree. But it’s his tale of persistence that makes his path to this year’s Midsummer Classic so inspirational.

“You get DFA’d, it’s essentially like being fired,” Blackburn said. "That was the main turning point. Being able to look past that and find that confidence in myself to push through that and get to where I am right now, I feel like it says a lot.”