Over the last two years, Zac Gallen has enjoyed what he deemed the best spot in the Diamondbacks’ clubhouse: in the far corner, next to the lost-and-found, where few people would bother him.

That changed this year, when home clubhouse manager Roger Riley assigned Gallen to a new spot on the southwest side of the Diamondbacks clubhouse, next to teammate Merrill Kelly. Gallen was a good sport about it.

“Alright,” he told himself. “Maybe there’s some good mojo over here.”

Kelly and Gallen just became the first pair of Diamondbacks pitchers to win back-to-back pitcher of the month awards since Randy Johnson and Curt Schilling accomplished the feat in April and May of 2002. Good mojo indeed.

Still, as lockermates — and the only members of the Diamondbacks’ 2019 starting rotation members who are still with the team  — Kelly and Gallen have developed a connection over the years that goes beyond their newfound status as co-aces of the Diamondbacks.

“It feels like we’ve been teammates for 20 years,” Gallen said.

When the Diamondbacks traded for Gallen in mid-2019, Marlins first base coach Trey Hillman had a parting note — albeit random — to share.

“I coached Merrill,” Hillman said. “Salt-of-the-earth kind of guy.”

Hillman managed Kelly’s Korean Baseball Organization team in 2017 and 2018, the two seasons that put Kelly back on the map as a big-league target and ultimately brought him to the Diamondbacks for the 2019 season. When Gallen arrived in Arizona in mid-2019, he quickly took to Kelly.

“He was super welcoming,” Gallen said. “Included me just in, you know, whatever, conversation on the bench, whatever it might have been.”

As pitchers, Gallen and Kelly don’t have much in common, other than the fact that they both throw a cutter and changeup. Gallen was good enough in Triple-A in 2019 to earn a call-up at the age of 23. He excelled out the gate. Kelly, meanwhile, spent five years in the minors and four years in Korea before earning a call-up at the age of 30.

This year, Gallen is fulfilling what many have long suspected: that the Diamondbacks have a Cy Young-caliber pitcher on their hands. Kelly, on the other hand, has elevated his status from league-average innings-eater to top-15 starter in the National League.

While Kelly has neared Gallen’s level of performance on the mound in 2022, the story is reversed on the golf course, where the two have spent a lot of time together since 2019. Although he acknowledges the gap has narrowed, Kelly is confident he still has the better swing.

“I would hope he would say the same thing,” Kelly said. “Otherwise, I think he’s probably shooting a little high.”

Gallen and Kelly are more than co-aces. They are friends.

“Sometimes it’s a business,” Gallen said, describing his relationships with teammates over the years. “It’s been cool to have a friend.”

“We’ve become pretty close over the last couple of years,” Kelly added.

Gallen and Kelly insist they do not normally compare performances with each other, but that hasn’t stopped assistant pitching coach Dan Carlson from trying to provoke them every now and then.

“Alright, you gotta one-up him,” Carlson will tell Gallen after a superb start from Kelly.

Gallen admits he has begun to buy in.

“Alright, you threw what?” Gallen jokes. “Let me see what I can do.”

“Just watching him go about his business every fifth day, it definitely pushes me to be better,” Kelly said. “I know when I see him go out and throw up seven innings with eight punchouts or 10 punchouts, it definitely makes me want to do the same thing.

“I think we’d be naive to think that we don’t see what each other are doing, especially when I have someone like that next to me.”

It would be equally naive to declare Gallen and Kelly as the next Johnson and Schilling, but they are unquestionably the best Diamondbacks’ starting rotation duo since 2018, when Zack Greinke and Patrick Corbin each tossed 200-plus innings with ERAs of 3.21 and 3.15, respectively.

In July, Kelly had a 1.31 ERA and 0.77 WHIP over 41.1 innings while holding opponents to a .168/.212/.266 slash line. By all accounts, it was the best month of his professional pitching career.

In August, Gallen posted a 0.68 ERA, 0.75 WHIP, 31 percent strikeout rate and seven percent walk rate over 40 innings. He allowed just three runs in the month, all of which came on Aug. 2 against the Cleveland Guardians. After that, Gallen rattled off 34.1 consecutive scoreless innings, the second-longest streak in franchise history. He will look to continue that streak on Sunday in the series finale against the Brewers.

For manager Torey Lovullo, there is a particular degree of confidence when Gallen or Kelly is on the mound.

“It’s a very comforting feeling to know that we have those guys going two out of the five days,” Lovullo said. “It’s plug and play. You just sit back, enjoy the ride for as long as you can, and see where it lands you. You know you’re gonna be in a good spot after they come out of the game. ”

Kelly already did that in his first start of September, tossing seven scoreless innings on Thursday with seven strikeouts. Winning another pitcher of the month award is not at the forefront of his mind, but he acknowledged how crazy it would be if that happened — and that he may have to battle Gallen for it.

“If it happens, that would be cool.” Kelly said. “Me, him, me. You know, maybe me and him can battle it out. See if he can get back-to-back or if I can get every other.”

With both Kelly and Gallen under team control through 2025, expect the duo to front the Diamondbacks’ rotation for three more seasons — and play a heck of a lot of golf in the process.

“They’re just good friends,” Lovullo said. “They’re good friends and they care about one another the right way.”

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Top photos: Rob Schumacher/The Republic