U.S. men’s national team manager Mauricio Pochettino appears headed for the exit door, a sudden move that will have deep implications for several Americans, especially his brightest stars.

According to several reports, the 54-year-old Argentine boss has already reached an agreement in principle to replace Manchester United manager Michael Carrick, who is reportedly set to be fired on Thursday.

Pochettino’s shock departure for the Premier League behemoths not only throws a wrench in the USMNT’s long-term plans—seeing the complete unravelling of the long-term, four-year contract he just signed, but will also seriously impact the young talents he has taken under his wing over the past few months.

No one will be more affected than 17-year-old prodigy Cavan Sullivan.

Sullivan Requires a Personal Champion—Pochettino Was the Perfect One

Despite his young age, Sullivan knows what he’s capable of. He just needs somebody to give him a chance.

It’s exactly what Philadelphia Union interim manager Ryan Richter did when he took over for Bradley Carnell midseason, paving the way for Sullivan’s unparalleled, record-setting dominance on the Major League Soccer stage. Richter saw a readiness in the young winger that Carnell had refused to see and immediately thrust him into the Union’s starting lineup, a decision he would not come to regret.

Mostly as a 16-year-old, Sullivan racked up eight goals and 10 assists in regular season play between Aug. 16 and Nov. 7 (13 games), directly influencing the Union’s 15-game unbeaten streak this fall—a club record—and the consequent surge from the depths of the MLS standings into automatic playoff positioning.

“I didn’t change as a player all that much,” Sullivan told Sports Illustrated back in September. “... [It was] having a new coach and one that believed in me. A lesson I learned—it was a tough one—is that not everyone is going to like you. It’s a tough lesson for a 14, 15-year-old kid.”

It was Sullivan’s domestic success that first caught the attention of Pochettino, who equally understood the value of giving the teenager big opportunities to shine and grow, even against some of the USMNT’s biggest rivals. The Argentine called up Sullivan, along with seven other teenagers, for the extended September-October international window last month, giving each of them key opportunities in the four fall friendlies, while leaving the likes of Christian Pulisic, Folarin Balogun and Weston McKennie at home.

Sullivan made his senior debut in the first friendly against Peru, finding himself in the starting lineup on the right flank after Pochettino opted for him over World Cup starter Sergiño Dest. Just two days before his 17th birthday, the budding star became the youngest player to debut for the USMNT in over 20 years since Freddy Adu in 2006. He immediately proved his worth.

Sullivan looked like a seasoned veteran against the South American foe and played an integral role in every facet of the team’s attack, stamping his characteristic swagger, attacking creativity and high soccer IQ all over the field. The Stars and Stripes left with a 4–1 victory, and Pochettino left awestruck, gushing over Sullivan’s “personality” on the pitch.

The performance warranted another start for Sullivan in the biggest match of the window: against Concacaf rival Mexico. He once again beat out USMNT stalwart Dest for the spot on the right flank, and just over an hour later, he became the youngest goalscorer in USMNT history. His sneaky chip over El Tri goalkeeper Raúl Rangel helped the Americans to a comprehensive 3–0 win over their most bitter rival, the first time the U.S. has beaten Mexico since Pochettino took over at the helm.

Talking to the press on Tuesday, Sullivan expressed his deep gratitude for Pochettino’s leap of faith, which has even extended to a second consecutive camp this November. The Concacaf Nations League will be Sullivan’s first competitive fixtures with the USMNT, and he could realistically retain his place within Pochettino’s starting lineup, perhaps manning the flanks alongside USMNT legend Christian Pulisic.

“Mauricio has taken me under his wing in the most tremendous way possible,” Sullivan said Tuesday. “I was obviously a young guy coming in, and he told me to just play free and be myself and have confidence in my ability.

“But that didn't mean I was let off the hook, or the standard was lowered for me. That standard remained the same for everybody in the camp, every training and every game. And I’m someone who really appreciates that, the directness on the field, but also the warmth, the hugs ... He’s a really personable guy off the field.”

Pochettino’s potential exit raises the question: What will happen to Sullivan?

Feasibly, the youngster has done enough by now to prove himself to even the most skeptical of managers who might only be interested in calling up seasoned veterans. But even if Sullivan continues to receive regular call ups to the national team by whoever replaces Pochettino, his development risks being seriously impeded if that successor cannot nurture Sullivan’s growth in the way the Argentine has—striking that perfect balance between “directness” and “warmth.”