With the aid of Aquilante and his father, Con, who runs a baseball academy in Hatboro, Schellenger has improved rapidly. A possible closer in the pro ranks, he throws a fastball that has topped out at 94 m.p.h.
"I can't say enough about how hard the kid has worked to get where he's at," Mark Aquilante said. "His work ethic is second to none."
Last season, while earning Inquirer second-team all-Southeastern Pennsylvania honors, Schellenger went 6-4 with a 1.19 ERA and 95 strikeouts - a single-season school record - in 67 innings.
The Malvern resident mixes a fastball, slider, and change-up.
"It's better to have three good pitches than four average pitches," he said.
In addition to his appearance at Yankee Stadium, Schellenger last summer was part of a Northeast region squad that competed in the Area Code Games in Long Beach, Calif. There, he was watched closely by major-league scouts.
"I usually get nervous in those situations," Schellenger said. "But now I'm kind of used to all of it. The key is not to overthrow. That's when your mechanics get out of whack."
Schellenger said he benefited from playing two seasons at Devon Prep with John LaPrise, now a sophomore middle infielder at Virginia.
"He told me, 'You have the potential to be really good,' " Schellenger said. "It was flattering to hear that from a player like him. I took that and ran with it."
In the offseason, Schellenger was visited by scouts from the Seattle Mariners, Texas Rangers, and Minnesota Twins. He will receive similar attention, with radar guns sprinkled behind the backstop area, this spring.
"It's definitely humbling," said the 18-year-old, an erstwhile basketball player. "Growing up, you dream of playing professional ball. You just don't know if it's realistic or not."