It was inevitable. Jon Duplantier was eventually going to allow an earned run, and it happened last night. After 21.2 professional innings with a 0.00 ERA, the Arizona Diamondbacks pitching prospect surrendered a pair of markers in the first inning of a game against the South Bend Cubs.

It’s worth noting that he’s not superstitious. That was the first thing about which I asked him when we spoke on Monday. Given that he was about to make his fourth start of the season for the Low-A Kane County Cougars, the last thing I wanted to do was jinx him.

Deplantier told me he used to be somewhat superstitious. Having found it mentally draining, though, he’s “pretty much scratched that” from his psyche. Addressing his run of perfection was thus perfectly acceptable. “Giving up runs is going to happen,” he told me. “If I never gave up a run… I don’t know how I’d be doing it, but I do know there’d be a lot of money to be made.”

He has a chance to make a lot of money. Arizona drafted Duplantier in the third round last year, and were it not for health concerns, he likely would have gone higher. The 22-year-old Rice University product has a classic pitcher’s frame — he’s listed at 6-foot-4, 225 pounds — and his fastball has touched 97. He’s currently commanding the pitch well, and he’s doing so with a delivery he trusts. Despite his injury history, the D-backs haven’t tinkered with his mechanics.

“If anything, they wanted me to go back to just throwing naturally, and not even think about mechanics,” Duplantier told me. “There are four or five things everyone needs to do in order to repeat a delivery, but outside of that, they told me they’re not going to micromanage my mechanics. It was kind of, ‘Hey, if you were to pick up a rock and throw it as far as you can, that’s how God wants you to throw that rock. As long as you’re feeling good, throw like that.’”

He hasn’t always felt good. Duplantier was on the shelf for his entire sophomore season because of a balky shoulder, and that was followed by a bout of elbow soreness. That gave scouts pause, but the righty remains unfazed. In his opinion, the maladies were related, and are unlikely to crop up again.

“Neither injury came from how I throw,” said Duplantier. “The shoulder thing came about from a neglect of certain muscles. I wasn’t doing arm care. I’d never needed to before, because I was always throwing a football. That was kind of my arm care, and when I stopped throwing a football, I stopped working out those muscles. The way I throw a baseball doesn’t fire those same muscles.”

According to the erstwhile Owl, the injury “had nothing to do with [his] arm, so to speak; it was [his] scapula, kind of the muscles in [his] back.”

Duplantier majored in kinesiology and sports medicine at Rice, and while he admits “there isn’t a 100% cause and effect,” he’s confident in his diagnosis of what occurred. That extends to what ensued with his elbow.

“I altered my throwing motion coming off the shoulder injury,” explained Duplantier. “Altering that motion — changing my arm slot — added a new stress. I had to recruit new muscles in my forearm, and tricep, that I’d never used in 21 years of life, to throw a baseball. Now my body has adjusted, and I’m throwing pretty close to how I was before the shoulder injury. Everything is fine now. In my eyes, I’m not a red flag, medically.”

Nor is he an Ivy League graduate with a pigskin pedigree — although that was nearly the case. Duplantier had an offer to play quarterback at Yale — other Ivies were interested, as well — but he opted to continue his education close to home, and to pursue a career on the diamond.

Duplantier hails from Katy, Texas, and not surprisingly, he has a relationship with The Rocket.

“I consider Roger one of my first pitching coaches,” said Duplantier. “I played with [Clemens’s son] Casey growing up, and they’ve told me if I need anything, to feel free to call. It’s cool to have a line of communication there if I ever need to reach out.”

That could happen someday if Duplantier decides to add a split-finger fastball to his repertoire. Based on advice he’s previously received from the Hall of Fame-worthy hurler, it would be a last-resort request.

“Roger showed [his splitter grip] to us when we were fairly young, but he gave some outlandish reason why we shouldn’t throw it,” explained Duplantier. “He said the pitch was more of a career reviver, so unless you feel your career is done, don’t even throw it. Something crazy like that.”

Based on his neophyte numbers — 11 hits allowed in 26.1 innings, with 36 strikeouts — Duplantier would be crazy to think he needs to start changing anything. He’s not perfect anymore, but that isn’t exactly cause for panic. Like he said, giving up runs was going to happen. Duplantier’s career ERA now stands at 1.03.