He went on to throw the pitch just twice later that evening when summoned for his Major League debut in what became an eventual 5-3 loss to the Dodgers. He didn't need it, though, breezing through the first five batters he faced by striking out four of them. Corey Seager stung him for a solo homer, though it hardly blemished the night for the former 36th-round Draft pick.
"It was awesome just running out and getting into a big-league game," Kiekhefer said. "Now I can officially say I'm a big leaguer. Unfortunately, I left one ball hittable there at the end. I just needed to execute one more pitch."
So impressed by Kiekhefer's first impression, manager Mike Matheny held him on the mound for a few extra words before making the pitching change.
"I told him it was a phenomenal job," Matheny said. "Despite the fact that we're losing and he just gave up a homer, what he just did was extremely good for a guy coming into his first game. I think he's going to very effective for us."
As for that changeup, look for Kiekhefer to feature it more frequently moving forward, particularly against right-handed hitters. He changed the grip on it last season while simultaneously working to sharpen his slider, which he hoped could become a weapon against left-handed batters.
The work continued in the Arizona Fall League, where Kiekhefer posted a 2.93 ERA in nine appearances, and into the spring, where he participated in big league camp as a member of the 40-man roster for the first time.
"This spring," Kiekhefer said, "gave me a lot of confidence when I got some swings and misses on those pitches."
The wider assortment of pitches is one reason the Cardinals think Kiekhefer may be more than just a lefty specialist.
"The weakest part of my game coming up has always been my offspeed pitches, and that hindered me a little bit to right-handed batters," Kiekhefer said. "Now I feel like, with the two-seam fastball and changeup, I have a pretty good mix to where I can get them out. If I need to come in and get one guy that's a lefty, I'll do that. But if I need to be able to eat up two or three innings, I want to be able to do that, too."
Kiekhefer, a 36th-round pick by the Cardinals in the 2010 Draft, is ranked by MLBPipeline.com as the club's No. 27 prospect. He allowed a .313 average to right-handed batters and a .105 average to left-handers in his 11 appearances with Memphis.
• Center fielder Tommy Pham, who is on rehab assignment with Double-A Springfield, went 2-for-3 with a home run and also robbed a homer in Springfield's 6-1 win on Friday. Pham suffered a left oblique strain on Opening Day and has taken 25 at-bats in his rehab stint.
• Right-hander Trey Nielsen, the Cardinals' No. 23 prospect, per MLBPipeline.com, threw the first complete game of the season for Springfield in Friday's win. Nielsen allowed one run on seven hits while striking out six.