How Butler’s Kyle Casteel and Nolan Stefaniak morphed into elite pitchers: ‘They did everything together’
Kyle Casteel’s name hadn’t even stopped echoing when he’d pulled up to a familiar spot Monday.
“Kyle gets drafted yesterday, he’s back in there this morning,” Battleground Baseball Group’s senior director of pitching Josh Sharpless said Tuesday. “I was in there for three hours. He was still there when I left.”
While Casteel, who was selected by the Chicago White Sox in the 11th round (No. 315 overall) of this past weekend’s 2026 MLB Draft and signed for $1.25 million a few days later, didn’t fire off pitches in the Callery training facility’s bullpen, he worked on agility and strength exercises and tossed the ball around with now-former Butler teammate and soon-to-be Penn State pitcher Nolan Stefaniak.
The day before, minutes after realizing a dream, Casteel shot Sharpless a simple text message: “I did it. I couldn’t have done it without you.”
Casteel began working with Sharpless as a ninth-grader, one year after Stefaniak. Sharpless also helped train Madden Clement, another Butler graduate who was taken by the Kansas City Royals in the 15th round (No. 449 overall), when he was in high school.
Sharpless called himself “1%” of the process for pitchers.
Along with Knoch graduate and former major league scout Chase Rowe, Sharpless helped Battleground get its start without a name or facility. During the COVID-19 pandemic, the operation moved into a “little shop off of Route 8, the Shaler area,” Sharpless said, and relocated once more — into the Hampton area — before planting its roots in Callery in 2023.
Success stories like Casteel and Stefaniak were what they’d always had in mind.
Casteel and Stefaniak have carried themselves as pros for a while, following daily routines in the training room and before games.
“They work so hard,” Sharpless said. “They work on their craft. They’re in the weight room. ... This past year and a half, the things they’ve done at Battleground with our strength and conditioning guy, Adam Vish ... they were at Battleground every single day, working out, working their program. It was like seeing professional pitchers on a daily basis, because they had routines.”
Both had their own warmup regimen lasting 45-50 minutes before each game that Sharpless likened to Paul Skenes.
“Those two weren’t normal (high school) pitchers,” Sharpless said.
Even after games, Casteel and Stefaniak — who Sharpless called “two peas in a pod” — ventured to Battleground, even if only to harp on mechanical particulars or do plyometric work.
“Just to try and feel details that they’re getting into their brain to be able to do on a consistent basis without thinking about it during a game,” Sharpless said. “Not everyone goes and does that kind of detailed work. The special ones do.”
Casteel had to undergo an evolution from where he was as a freshman. Sharpless remembers him being “quiet and kind of undersized” with a smooth arm motion, but he had a feeling Casteel would eventually get bigger, like his older brother, Colin, who Sharpless also trained.
“I just said, ‘Once Kyle grows and once he develops into his body, something special’s gonna happen here,’” Sharpless said. “Sure enough, the winter of his junior year is when he started to grow and get stronger.”
Casteel jumped from throwing 85 miles per hour that January to 92. Colleges soon reached out. Shortly after came his commitment to West Virginia.
“It looked like he wasn’t really trying,” Sharpless said.
Stefaniak, meanwhile, always had a lively arm. Sharpless likened him to Bull Durham character “Nuke” LaLoosh, saying: “He had this golden arm, but he had no idea where the ball was going. He would throw it halfway at the backstop.”
They focused his development primarily on timing, repetition and crafting a breaking ball.
“His hat fell off his head for two years straight because he was so violent (throwing),” Sharpless said.
The two pitchers grew together and did seemingly everything together — working out, throwing live sessions in the winter, monitoring Trackman devices.
“If one guy was throwing 94, the other guy would try to throw harder.”
On Tuesday, Sharpless talked with Stefaniak, who operated with a “win-win” attitude during the season and leading up to the draft. He spoke just as glowingly of the opportunity to play Division I baseball.
“There’s probably a level of disappointment, but I think he’s in a really good headspace,” Sharpless said. “He’s eager. He’s excited to go to Penn State. (Assistant coach Will Jauss is) very good on the analytics side of things as far as figuring out different types of pitches.
“So I think (Nolan) is gonna thrive there.”
Stefaniak will be draft eligible after turning 21 in two years.
“You’re probably gonna hear his name called then,” Sharpless said.
