ALLENTOWN - The brothers were born eight years apart - the older one a basketball junkie who moonlighted for a time as a pitcher, the younger one forever smitten by the summer game.
Growing up in Carlsbad, California, just north of San Diego, the older brother would fire pitches off a cinder-block wall next to the family's garage – the wall that always had an upright rectangle scrawled upon it, representative of a strike zone.
In time the younger brother would make use of the same wall. At that point he dreamed of being a shortstop, but in time he too gravitated to the mound. And his older sibling - indeed, his only sibling - would see some random Padre or Dodger pitcher on TV and immediately repair to a nearby Little League field, his brother in tow, to see if the kid could master some mechanical quirk of the big leaguer.
Always and forever, the older man serving as his brother's keeper.
The result being that all these years later, the kid in question - Tom Eshelman - hopes to become a keeper of another kind with the Phillies.
The 22-year-old right-hander is 4-0 with a 1.38 ERA for Triple-A Lehigh Valley, his most recent victory a 12-1 domination of Buffalo on Monday in which he surrendered that lone run on five hits over seven innings, while striking out six. He didn't walk a batter, but then again, he seldom does; command has always been his calling card.
Before that, he was named International League Player of the Month in May. Before that, he went 3-0 with a 3.10 ERA at Double-A Reading, leading to his promotion on May 8.
And way, way before that, the aforementioned older brother, Sam, helped bring out the best in him.
It should probably come as no surprise that Sam now teaches middle-school English, or that he just completed his first year as the varsity hoops coach at Carlsbad High, the brothers' alma mater. He said on the phone Tuesday afternoon that his baseball knowledge was "rudimentary" back in the day, and called his work with Tom "an opportunity to experiment around a little bit - teaching and coaching and seeing how different things would work."
Sam's interest could almost be described as paternal. But it was not, he insists, Pavlovian.
Which brings us to the shock collar.
Two years ago Chris Foster of the Los Angeles Times profiled the younger Eshelman, and mentioned the time Sam looped such a collar around his brother's neck. Maybe, Foster wrote, that was the reason Tom became such a chronic strike thrower; his brother activated the thing every time he missed the zone.
The reference appeared to be tongue-in-cheek, but on Tuesday both brothers felt compelled to clarify things anyway.
"That story kind of got turned around a little bit," Tom said before a game against Buffalo was rained out. "The whole bark-collar thing, that wasn't true."
Sam called it "a childhood prank between brothers," a case where they were "just messing around in the back yard, brothers being brothers."
"That got misrepresented as a training method," he added, "which it wasn't."
Sam gave up baseball before high school, choosing instead to concentrate on basketball, the same sport the boys' dad, Dave, had played all the way through junior college. (Dave now runs his own business, while his wife Rosemary is a school administrator.)
Tom, a self-described "rebel," plotted a different course.
"He was more so committed to just baseball, and he really loved the game," Sam said. "And he took off running with it."
But, again, seldom walking anybody. That has been a constant. That's partially because of Sam's help, partially because Tom gained a better understanding of his craft while doubling as a catcher in high school, partially because other pitching coaches - a freelance guy named Dominic Johnson in San Diego County, and Jason Dietrich at Cal State-Fullerton - worked with him along the way.
Eshelman issued exactly 18 bases on balls in 376.1 innings over his three seasons at Fullerton, while going 28-11 with a 1.65 ERA and 321 strikeouts. That led the Astros to draft him in the second round in June 2015.
Six months later they sent him to Philadelphia as part of the Ken Giles trade, and in his first year in the Phillies organization he went 9-7 with a 4.25 ERA while splitting time between Clearwater and Reading.
"He wasn't satisfied with where he was at," Sam said. "He worked hard to put himself in position to succeed."
Tom is now fully healthy, after seeing his 2016 season cut short by an appendectomy. His fastball, clocked in the low 90s, has a little more movement, his slider a little more bite. Ironpigs manager Dusty Wathan, who also had the 6-3, 210-pound Eshelman in Double-A last year, added that the young right-hander has a better understanding of the tighter strike zone seen in the high minors, and that he is hiding the ball better during his delivery.
"He breaks more bats than anybody I've seen, the last couple years," Wathan said. "It's five or six a night, which is impressive. People say he doesn't strike many guys out, which is true, but if you're breaking five or six bats a night, they're not swinging and missing, but they're definitely not hitting it where they want."
Eshelman has, in fact, struck out a pedestrian 31 in 45.2 innings.
He has walked just four.
As for Sam, he streams his brother's games from afar, and keeps in touch.
"As much as I can, I try to help him with the mental side of things - just playing the big-brother role," he said. "It's all out of love."
And all with the idea of making him a keeper.