PHILADELPHIA -- As of Sept. 1, neither D-backs left-hander Andrew Saalfrank nor Phillies right-hander Orion Kerkering had thrown a pitch in a big league game.

Now, each could be tasked with recording key outs when their clubs square off in the National League Championship Series -- and though they find themselves in similar situations in October, Saalfrank and Kerkering have taken very different journeys.

The 26-year-old Saalfrank began the year at Double-A Amarillo, looking to carve out a role after missing the entire 2021 season due to Tommy John surgery and spending most of '22 with High-A Hillsboro. A sixth-round Draft pick out of Indiana in 2019, Saalfrank never cracked the D-backs' Top 30 prospects list.

The 22-year-old Kerkering, on the other hand, entered 2023 ranked as Philadelphia's No. 21 prospect. Still, the Phillies' fifth-round pick in the 2022 Draft from the University of South Florida was well off the big league radar when he started the season with Single-A Clearwater.

Saalfrank pitched well for Amarillo and Triple-A Reno -- posting a 2.53 ERA over 64 innings -- before making his MLB debut on Sept. 5. Kerkering cruised through the Phillies' system, putting up a 1.51 ERA over 53 2/3 innings across four levels of the Minors (including just one appearance at Triple-A Lehigh Valley) before making his debut on Sept. 23.

Though obviously uncommon, it's not entirely unprecedented for a postseason-bound team to dip into its Minor League system to take a late-season flier on a big arm.

The ultimate success story is Francisco Rodríguez, who made his MLB debut for the Angels on Sept. 18, 2002. Just 20 years old at the time, K-Rod pitched only 5 2/3 innings over five regular-season appearances before not only cracking the playoff roster, but playing a pivotal role in the club's World Series run. He went 5-1 with a 1.93 ERA and had a ridiculous 28 strikeouts over 18 2/3 innings in the postseason.

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And there lies the one thing Saalfrank and Kerkering have most in common: strikeouts.

Saalfrank racked up 93 strikeouts over 64 Minor League innings (13.1 K’s per nine). Kerkering had 79 in 53 2/3 frames (13.3 per nine). Prior to his late-season promotion, Rodríguez had racked up 120 strikeouts over 83 1/3 innings in the Minors -- an average of 13 K's per nine.

It's that type of dominant stuff that led to a September promotion for both Saalfrank and Kerkering.

Though nowhere near the K-Rod level yet, Saalfrank has already notched some big outs in October -- none bigger than in Game 2 of the NL Wild Card Series against the Brewers in Milwaukee. With the D-backs clinging to a three-run lead, manager Torey Lovullo turned to his rookie left-hander with the bases loaded and one out in the eighth. Saalfrank induced a pair of groundouts to escape the inning unscathed.

"What are you going to give me? Are you ready for this?" Lovullo said afterward. "He had given me -- in every outing prior to this -- he had given me every reason to believe he was ready for this opportunity."

Albeit with a seven-run lead, Kerkering also helped the Phillies close out their NL Wild Card Series with a perfect eighth inning in Game 2.

Entering the NLCS, Saalfrank has thrown 1 1/3 scoreless innings over three postseason appearances. Kerkering, who pitched only three innings during the regular season, has allowed just one hit and one walk over three scoreless frames in the postseason.

“I don't think anything different,” Kerkering said of his approach to pitching in the postseason. “I just keep going. It's the same mound every time. Just keep doing what I can do best and help this team win.”

Over the previous 10 seasons, 10 relievers had pitched in the postseason after making their MLB debut after Sept. 1 that same season and only two of those 10 late-season debutants went on to pitch more than five innings in the postseason. Brandon Finnegan had a 10.50 ERA in seven appearances for the 2014 Royals, while Hunter Strickland put up a 7.56 ERA in eight outings for the Giants that same season.

Even the ones with remarkable September success tended to have limited chances in October. In fact, none pitched better down the stretch than Kervin Castro, who -- similar to Saalfrank -- had 13 1/3 scoreless innings following his Sept. 7 debut for the 2021 Giants. But even he managed just 1 1/3 postseason innings before San Francisco's NL Division Series exit.

So despite little track record for what the D-backs and Phillies are asking for out of Saalfrank and Kerkering, respectively, don’t expect their skippers to shy away from calling on them in big moments in the NLCS.

“I've spent a lot of time with young players -- a lot of time in the Minor leagues -- so I tend to trust them,” Phillies manager Rob Thomson said. “In order for them to get confidence, you've got to use them and you've got to show confidence in them. And then the talent will come out.”