Zach Penrod’s left arm has always been the center of attention. Standing at 6-foot-2, 210 pounds and throwing his fastball in the upper 90s from the left side, his potential has never been denied.

But on an August night in Missoula, Mont., Penrod's left arm was -- quite literally -- on full display.

“He comes in to close a game in this sleeveless jersey, throwing 98 mph with this wipeout 87 mph slider and it was the funniest thing I’ve ever seen,” Missoula manager Michael Schlact said. “He was all business and just wanted to win.”

The Paddleheads, formerly the Osprey, were donning their sleeveless uniforms as a part of a throwback jersey promotion.

“It’s independent ball, why not?” Schlact remarked.

The moment was a unique and fitting encapsulation of Penrod’s journey through baseball. He has dealt with injuries, cold nights in a high school facility -- working floor installations -- and reconstructive elbow surgery.

Since he threw on a sleeveless jersey as a member of the Paddleheads in August, he has pitched in the Single-A postseason for the Greenville Drive and recorded multiple scoreless appearances in the Arizona Fall League.

Penrod spent the past six weeks pitching in the AFL. He finished the circuit ranked second in ERA at 1.29 and the best among starting pitchers. Penrod tossed 14 innings, allowing just three runs (two earned) on nine hits, with opponents hitting .184 against him.

For his efforts, Penrod was selected to the Fall Stars Game. He threw a scoreless frame, allowing one hit while striking out one. He set down Benny Montgomery (Rockies' No. 8) and Jacob Berry (Marlins' No. 4).

Signed by the Texas Rangers out of Northwest Nazarene University in 2018, Penrod tossed 11 2/3 innings in the Rookie-level Arizona Complex League that season. He was a converted outfielder, having pitched a combined 32 1/3 innings in his college career. He also pitched in the West Coast Collegiate Summer League.

“I was feeling some shoulder stuff after throwing that many innings for the first time,” Penrod said. “It was a lot.”

While he was with the Rangers, Penrod befriended Austin Bibens-Dirkx. Now a coach in the Toronto Blue Jays organization, Bibens-Dirkx had just finished a year in which he threw 45 innings with the Rangers in the bigs.

“I worked out with him in the offseason and saw how he prepared,” Bibens-Dirkx said. “I’m not typically one to put my name on people unless I truly believe that they will work their butts off, do what needs to be done and make it so I don’t look bad. I took it very seriously when I gave the Rangers his name. They liked what they saw, but he was unable to stay healthy.”

Penrod suffered a left UCL injury that required Tommy John surgery in 2019. He was placed on the 60-day injured list on June 17, 2019. Despite being activated that September, he did not appear in a game before he was released on June 1, 2020.

“It was tough,” Penrod said. “If I didn’t have my support base after that tear, surgery and building back up, I don’t know what I would have done. I wouldn’t be doing this still without them.”

So, Penrod went home to Nampa, Idaho.

His father owned a construction business. During the offseason, Penrod took 10-hour shifts installing floors. But, he still had to stay fresh on the mound. His high school had just built a new training complex. It did not have heat inside, but it was enough. Penrod would go in and throw from 9-11 p.m. every night.

“I would go in, do a quick warmup and then aim for 75-90 throws,” Penrod said. “If I felt good, I would throw harder. And if I didn’t feel good, I would shut it down.”

Penrod even had his fix of live hitters with his youngest brother and his friends.

“That competition was there,” Penrod said. “I wanted to show they couldn’t hit me, and it was nice to see some batters in the box. They’re in high school, so they put up a good fight.

“I can’t thank them enough. My wife, my entire support system. Without them, I wouldn’t be here.”

Penrod joined the Boise Hawks in the Pioneer League in 2021. That year, he pitched to a 3-4 record with a 5.66 ERA in 68 1/3 innings across 14 outings.

“I set out at the beginning of this year with a few goals,” he said. “It was looking like it was going to be my last year if something didn’t really swing in my direction, and so I set out with the goals of staying healthy, having fun and winning a championship.”

Then, in 2023, with a 2.98 ERA in 54 1/3 frames under his belt with Missoula, the Boston Red Sox noticed.

“It was a very short process,” Penrod said. “They reached out in August, they asked for information about me. Then, my coach called me and told me that the Red Sox were pretty close to [signing me]. I was like, ‘Oh yes, absolutely.’ They called me, offered me a contract ... The next day at noon, I was on a flight to Winston-Salem to meet the team.”

Penrod stepped into an intense environment. Greenville had won the first half of the regular season, and when southpaw came in, he was immediately expected to pitch in the postseason.

He was paired with current Glendale Desert Dogs manager Iggy Suarez, who was in the midst of his 10th season in the Red Sox organization.

“From him coming from independent ball, his age and his drive that he still has to come in and hit the ground running was impressive,” Suarez said. “You sometimes don’t know how the mentality is with someone coming from independent ball, but when you see him and the way he’s performed, it's probably fast for him. But the first thing he said was, ‘Man, this is a lot of fun!’ If it's fun for him, it's fun for us watching.”

Suarez, Bibens-Dirkx and Schlact all commended Penrod’s mentality.

“He showed up every day with his feet underneath him,” Schlact said. “He showed up and wanted to win here. There was no inkling of, ‘I wish I could be somewhere else,’ with him.”

Penrod received 20 2/3 innings during the regular season with Greenville. He posted a 2.18 ERA with 20 strikeouts and 11 walks. In the postseason, the 26-year-old was the winning pitcher of record in Greenville’s title clincher against Hudson Valley. He tossed five innings of two-run baseball out of the 'pen.

“He's a lefty, with the mid-to-upper 90s fastball and being able to have that slider and cutter to throw in any count makes him really dangerous,” Suarez said. “He’s a workhorse, he’s going to throw until he tells us. If I ask him how he’s feeling, he always wants to keep throwing. He has the strength, he’s not a little guy and he’s a strong lefty. I was very comfortable throwing him in the postseason.”

Penrod was notified of his Fall League assignment in September.

“I got called into the office after a really good outing and I thought I was getting called up,” Penrod said. “They asked me if I had ever heard of the Arizona Fall League and I was like, ‘Heck yeah!’ I had guys I knew when I was with the Rangers who came through here and made the Major Leagues, so I knew it was a great opportunity for me.”

Still, he had to tell his bride-to-be that he was going to Arizona for the circuit, a time in which he was supposed to get married. His wife took the news in stride and accompanied him to the desert to offer her support. They wed at the end of the AFL’s third week.

“I owe her,” Penrod said with a smile.

Now, Penrod will take a short period of well-earned rest before ramping back up for Spring Training.

“I just enjoy the moment. I know how quickly those injuries can come back and how they can play a huge role in keeping you off the field and derailing your progress,” Penrod said. “You’ll think about it, but at the same time, every time I can go out there and be healthy, I can appreciate it much more. I keep having fun, that’s what got me here and it's going to keep moving me forward. Whatever comes after that is a bonus.”