MESA, Ariz. — While the A’s assemble for their first workout Wednesday, one of their former top starters is forging a new path for himself.

At just 29, Jarrod Parker is officially retiring from the game in which he fought so hard to stay after two hideous elbow injuries. He told The Chronicle this week that all that remains is the paperwork.

“I’m not entertaining any offers, let’s put it that way,” Parker said. “I’m just working through the logistical stuff.”

Parker is nearly two years removed from his second surgery for a fractured medial epichondyle bone in his right elbow. He has recovered well, healthy except for what Parker describes as a “gnarly scar,” unsurprising after two Tommy John surgeries and two surgeries for broken elbows.

“I’m doing everything but throwing,” he said. “Your arm will tell you when it’s done, and it did. It just sucks, being somewhat younger.”

That’s a real shame, for Parker was a budding star. In 62 career starts, he went 25-16 with a 3.68 ERA. In 2012, at the age of 23, he put up a WAR of 3.9, best on the team and 10th best in the league. He finished fifth in Rookie of the Year voting. Some of those ahead of him: Mike Trout, Yoenis Céspedes and Yu Darvish, all recipients of $100 million-plus contracts.

“When people ask me the best pitcher I’ve ever seen, I always tell them Jarrod Parker,” said former A’s reliever Ryan Cook, who arrived with Parker in a trade with Arizona. “His ability was pretty special. It’s so unfortunate baseball didn’t get to see him pitch longer, because he was amazing to watch.”

Parker was expected to be an anchor, along with Sonny Gray, of a good young Oakland rotation, but in 2013, he tore his ulnar collateral ligament for the second time (his first Tommy John surgery came when he was with the Diamondbacks).

“He was one of the most talented young pitchers in the game, and the organization was at such a critical point of playoff runs,” vice president of baseball operations Billy Beane said. “To have a guy with that kind of talent, and boom, he’s extracted — that was a huge blow.”

Parker did everything possible to return — in retrospect, probably too much and too fast. Experts recommend adding at least six months to a year to a second Tommy John-surgery recovery timeline, and Parker was throwing in games 13 months later. His elbow broke on a pitch during a rehab start with Triple-A Nashville on May 8, 2015, a gruesome sight.

“I was charting pitches in the stands and it was just surreal,” said former A’s pitcher Barry Zito, who spent most of 2015 with Nashville. “It was crazy, you’re watching the ball fly toward the third-base dugout and you think of Dave Dravecky and Tony Saunders and Tom Browning.”

“Horrific,” Beane said. “It’s traumatic to be injured in such a violent way when pitching, and after all that rehab, just heartbreaking. Really, a career interrupted.”

Parker tried to come back even after that broken elbow, going through another 1½ years of rehab, but his comeback ended March 11, 2016, when the same area of his elbow fractured again. His final surgery, three weeks later, was primarily to stabilize his elbow for everyday life. Orthopedists said it would be all but impossible for him to resume his baseball career; in Tommy John surgery, the ulnar collateral ligament is re-attached to the tiny epichondyle area, and Parker’s was obliterated.

This time last year was Parker’s first without baseball, and he struggled with it. “That was tough,” said then-roommate Cook. “He was down in the dumps for a while.”

“I still had that baseball feel last year,” Parker said. “This is my second year away, and it’s easier. I’m keeping in touch with a few guys and I’m able to be a fan again. I don’t hate it too much.”

Parker got married in October; his wife, Lauren, is a dentist with a practice in Nashville. He, too, would like a career in the health industry after seeing it up close for so many years — perhaps becoming a rehab coordinator or opening a performance institute for top-level athletes. Parker is educating himself about the field and looking into certification options with the goal of using his difficult experiences to help others.

“I’d like to pass along that knowledge and information,” he said. “I know the mental battles — and I know there is light at the end of the tunnel.”

Parker has conferred with several big-league pitchers going through rehabs, including Cook, who had some complications while coming back from Tommy John surgery, and Angels starter Tyler Skaggs.

“Just being able to talk to Jarrod was great,” said Cook, who is fully healthy for Seattle’s spring camp. “I could say, ‘Hey, man, is it normal to feel this or that?’ I think he’d be a perfect fit for anything where he’s helping recover from injuries. Let’s face it: He knows. He’s had so many surgeries and fought through so much adversity. He can empathize — and he knows what it takes to pitch at a high level.

“It’s great to see him now and the transition he’s made. Jarrod is his old self again.”

Zito runs into Parker around Nashville — they live in the same neighborhood.

“It’s pretty mind-blowing to be done with the game at that age when you have that kind of talent, unheard of, really,” Zito said. “With everything he’s been through, the guy is an inspiration.”

Susan Slusser is a San Francisco Chronicle staff writer. Email: sslusser@sfchronicle.com Twitter: @susanslusser