PHILADELPHIA — Casey Chenoweth tuned into the Home Run Derby from his couch in Northwest Arkansas on Monday night.He didn’t need to be on site at the MLB All-Star festivities to know Jordan Walker was locked in. There Walker stood in the batter’s box during the championship round, hat backward, chains stacked around his neck, wielding an Iron Man bat.Walker didn’t waver as he whacked homer after homer deep into the July night, undeterred by the relentless booing from the Philadelphia faithful as he neared the total of hometown favorite Kyle Schwarber.Walker needed 11 big flies to tie Schwarber, 12 to become the first St. Louis Cardinal to win the Home Run Derby. He sat at six, with two swings left. Then he unleashed one heck of a run. Walker barreled six straight homers, capped by a majestic 407-foot blast to win it all. The comeback marked one of the most memorable derbies in recent memory.“It was absolutely epic,” Chenoweth raved during a phone call with The Athletic on Tuesday afternoon. “So cool to see.”Perhaps nobody is better suited to marvel at Walker’s recent success than Chenoweth, an assistant hitting coach for the Cardinals and one of Walker’s closest confidants in the organization. He understood Walker’s journey, as he fell from a 2020 first-round pick and a top overall prospect to enduring several demotions to the minor leagues amid serious questions regarding his long-term future.Now, Walker’s long-awaited arrival to national baseball prominence is here. Sparked initially by the spunky first-half play of the Cardinals and fueled Monday night by his dramatic homer barrage, the baseball world is beginning to take note of St. Louis’ budding right fielder.“He was able to show the world exactly who he is and what he’s capable of,” Chenowith said.Once the face of promise for one of baseball’s winningest organizations, Walker’s struggles over the first three years of his career instead turned him into the poster child for the Cardinals’ severely outdated player development system.It was Chenoweth — with considerable help, communication and input from Cardinals assistant general manager Rob Cerfolio, manager Oli Marmol and hitting coach Brant Brown — who found a way to break through to Walker when the Cardinals elected to stretch out a rehab assignment with Double-A Springfield last year.The hope was that Walker would benefit from one-on-one instruction under Chenoweth, a minor-league hitting coach at the time. Walker had all the tools: the swing speed, the exit velocity, the speed, the power. But he did not have the results.Perhaps he needed a fresh voice from within the organization.Almost immediately, Walker took to Chenoweth’s intentional coaching style. In return, Chenoweth learned quickly what would resonate with him.It’s fitting, Chenoweth said, that Walker’s derby win happened in such fashion.“It was an uphill battle for him for sure, going into that last round,” Chenoweth said. “But I think that’s kind of been his career. Back against the wall, a hill to climb.”Walker’s ascent comes at a time the Cardinals have fully embraced a youth movement. It’s easy to forget that after all he’s endured, Walker is only 24. There is plenty of time for him to fulfill his potential.He always believed he would.“I never really doubted that I’d be able to do this at some point,” Walker said from the dugout tunnel before the American League topped the NL 4-0 in the Midsummer Classic on Tuesday. “It was more like, ‘When is it coming?’”The power swing Jordan Walker displayed Monday night wasn’t always apparent. It took some deeper conversations to unlock his potential. (Emilee Chinn / Getty Images)The marine layer had started to roll over Oracle Park when then-president of baseball operations John Mozeliak acknowledged a looming decision before an early-season game against the San Francisco Giants. It was April 26, 2023, and the longtime executive was in distress. His ballclub, fresh off a division championship and a demoralizing first-round elimination, was off to its worst start since 1973.