This story was excerpted from Steve Gilbert’s D-backs Beat newsletter. Jesús Cano pinch-hit on this edition. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

PHOENIX -- When Justin Martinez was recovering from Tommy John surgery in 2021, he often found himself laying in his bed, staring at the ceiling and holding his right shoulder to alleviate the pain from the procedure.

Even in the midst of one of the toughest challenges in Martinez's career up until that point, the hard-throwing right-hander was determined to not let the small detour on his road to the Majors prevent him from reaching his potential.

More than three years later, the 23-year-old pitcher has cemented himself as one of the most reliable arms in Arizona's bullpen. And while D-backs manager Torey Lovullo won’t label any relievers as the closer, it’s clear based on Martinez’s six consecutive saves in August that there is plenty of trust in him to be on the mound with the game on the line.

“It's hard to believe he is 23 years old,” Lovullo said. “He's very physical, very imposing figure when you stand next to him, he's got a pretty intense competitive spirit.”

After his surgery, Martinez ascended through three levels in the Minors in 2022, and he pitched in the Arizona Fall League before making his MLB debut on July 7, 2023. There was no question he had the tools to be a dominant reliever, but early command issues saw him bounce between Triple-A Reno and the Majors and miss out on playing in the D-backs' World Series run.

Instead of waiting for his opportunity in 2024, Martinez decided to get a head start. He returned home to his native Dominican Republic over the winter to fine-tune his breaking pitches, something that has propelled him to success. It also helped that the notoriously rowdy crowds of the international winter leagues prepared him for the pressure he’d feel closing out games.

“It’s my job and responsibility,” Martinez said. “I’m trying to be the best version of myself to help the team keep winning games during this important stretch. It’s a big responsibility, but I have to keep working hard whenever it’s time to pitch the ninth inning.”

Martinez’s fastball ranks in the 91st percentile or better in average exit velocity, whiff rate, strikeout rate, barrel rate and hard-hit rate. And to no surprise, he sits in the 100th percentile for average fastball velocity.

But Martinez's secondary pitches can carry that same speed. Hitters have a .076 average and a .091 slugging percentage with a 52.7% whiff rate against his splitter, compared to a .129 batting average with a 48.8% whiff rate versus his slider.

As a reliever, it’s hard to showcase a breakout performance in a single game when you’re only tossing an inning or two. But Martinez took advantage of his strong performance on the road against the Dodgers on July 4, when he struck out five batters -- including Freddie Freeman, Teoscar Hernández and Shohei Ohtani -- over three innings, also earning the win.

But as he walked off the mound after finishing his job, Martinez wasn’t focused on the accolades. Instead, he was proud that he put the D-backs in a position to win a key series over their division rival.

“I’ve always believed in my talent,” Martinez said. “I’ve always worked hard to get the results I’ve wanted. It’s not surprising to me, because I trust in my talent and the work it took to get here.”

As quiet and calm Martinez is on the mound in high-pressure situations, he has a bright personality that has made him a favorite in Arizona’s clubhouse with the way he carries himself. The rookie said that the camaraderie and culture the D-backs have cultivated this season make representing the team on the mound much more rewarding.

“He’s very fun and joyous to be around,” Geraldo Perdomo said. “He loves working on the small things when on the mound, but he also enjoys having fun with what he’s doing.

“I think that’s the best characteristic he can have right now. If you ask anyone in the clubhouse, they’re going to tell you the same thing, because he’s a great player and an amazing teammate.”