GOAL takes a look at where Sullivan stands five matches into the 2025 MLS season, and what to expect this season
It was March 2024, and Apple TV analyst Taylor Twellman was gushing, posting on social media that Manchester City scouts believed Cavan Sullivan was the "best 14-year-old in the world."
A member of the Philadelphia Union academy at the time, Sullivan went on to break Freddy Adu's record that summer by becoming the youngest player to debut in MLS, and signed the largest homegrown deal the league had ever seen – which included a clause that, upon turning age 18, he would join the Premier League giants in Manchester.
A U.S. youth international across various age groups, with continental competition experience at the youth level, Sullivan is a bonafide rising star. The 15-year-old has even expressed his ambitions to be a member of the USMNT's 2026 World Cup squad, even though he would only be 16 when the tournament kicks off.
In the modern game, could a 16-year-old be a relevant game-changer?
Lamine Yamal led Spain to a EURO title last summer at 17. Pele led Brazil to a World Cup win at 17 in 1958. Kylian Mbappe was 18 when he helped France to a World Cup win in 2018. Michael Owen, at 18, scored twice for England at the 1998 World Cup. In 2014, 19-year-old Julian Green scored with his first touch off the bench for the USMNT in a quarterfinal against Belgium.
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Some teenagers have become regular contributors at the professional level, but more often than not, those who remain contributors beyond their teenage years? They tend to be considered into generational talents.
On the contrary, there also have been teenagers labeled generational after breaking out at a young age who, a decade into their professional careers, are looked at as "could have beens." The list is long, from Alexandre Pato and Hachim Mastour to Bojan Krkic and Ravel Morrison and – most notably from a U.S. perspective – Adu.
There's a certain care that needs to be taken with child prodigies, of course, but at the same time, if they're ready, should they held back? Slotted as the 30th-best teenager in the world on GOAL's most recent NXGN rankings, Sullivan has the potential to be one of the greatest soccer players the country has ever produced.
Which begs the question: where is he? Why is he not a regular with Philadelphia's senior side in MLS? What is his timetable? GOAL takes a look at the 15-year-old's development since signing his contract last summer, where he stands with the Union, and what the next few months have in store.
GettyWhere he stands with Philadelphia
Sullivan made three appearances for the Union senior team during the 2024 regular season, playing 10 total minutes at the MLS level under then-manager Jim Curtin, including his emphatic debut.
In MLS NEXT Pro in 2024 with Union II – their developmental team – he started 13 matches and made 18 appearances, scoring five goals and recording four assists during the regular season. In the playoffs, he started all four matches en route to leading Union II to the championship game, scoring in a 4-0 semifinal victory over Crew 2 and recording a secondary assist in the title game against North Texas SC – a 3-2 loss.
The calendar year served as his emergence onto the league's biggest stages. However, after the completion of the 2024 MLS season in which the Union's senior team missed the playoffs, Curtin was fired and a shift in identity occurred. Former St. Louis CITY SC manager Bradley Carnell was appointed, and through five matches, the Union sit on 12 points and are atop the MLS Supporters' Shield standings.
The senior team is flourishing under the leadership of the South African manager, with Cavan's older brother, Quinn, locked in a starting role in the XI alongside other seasoned veterans and talented players.
Where does Cavan fit into a team of already-proven MLS caliber players? For Carnell and the Union, it's become a careful consideration, as they establish the identity of the Eastern Conference side, while balancing the fact that Cavan is inching closer to the senior squad.
AdvertisementUSA Today SportsExpectations and advancement
Ahead of the 2025 season, Apple TV released the docuseries "Onside: Major League Soccer" looking back at the 2024 campaign and focused on the league's growth and development. The third episode centers on Cavan, documenting his rise into the professional ranks of MLS. It paints the picture of Sullivan's journey to becoming arguably the league's most anticipated prospect.
“Yeah, I got a target on my back. But I love it,” Sullivan says in the series. "It’s another chance to show how you can handle the other team coming out to get you.”
Those expectations are now a reality, competing against adults and fighting for the chance to prove himself within the program. His age is, in part, is what makes him so unique. Yet on the squad, he still has to perform.
“You’re a professional now,” Union veteran and former captain Alejandro Bedoya says to Sullivan in the episode. “You’re playing with big boys, you know what I’m saying? We’re men here. This is our livelihood. Everybody has got to earn their spot. I don’t care who you are. You’re a new player on the team. You got to earn it.”
Quinn Sullivan, meanwhile, is providing space to allow Cavan to learn the hardships of the game, while also offering the support expected from a big brother.
“I’m sure he’ll get knocked around, and that’s part of it, right? But you have to find the fine line between being the protector and letting him do his own thing,” Quinn says in the series as a clip of Cavan on the ground in pain surfaces on screen. “I have to let him learn the lesson of, ‘OK, you take too many touches, you’re going to get hit, right?’”
And for his part, Carnell is not going to let hype surrounding Sullivan dictate his coaching decisions. He's going to make Cavan fight for his spot in the team.
“We have players on the roster all eligible for minutes, and he falls into that category,” Carnell said of Sullivan ahead of Matchday 2 of the season. “And minutes need to be earned. I’m not just dishing out minutes here, just because of whatever name’s on the back of a shirt.”
Getty Images SportNext steps in the journey
Philadelphia have taken a cautionary approach to Sullivan's advancement. He might be a prodigy, one that might someday be considered a generational talent, but those are all hypotheticals – even with an external agenda being pushed. Putting immense expectations on the shoulders of teenagers can be risky, as can asking them to do more than they are capable of during the development process.
Look to history – there are countless examples.
Pato, who made his AC Milan debut in 2008 age 18, became the darling of the football world over a two-year period, breaking out for the and the internationally. He was supposed to be the striker of a generation, the forward who changed the game entirely. By 2013, age 23, Pato was back in his native Brazil signing with Corinthians.
"I partied too much [in Milan]. I had no desire. I was living in a fantasy world. But when I wanted to speak, I was told to 'Focus on my football.' I was too young to disagree," Pato told the Players Tribune in 2022. "Really, I was just a kid."
The Brazilian never lived up to the term prodigy; he bounced around Europe and Asia, and even had a stint in MLS, but never filled the boots that expectations said he needed to. What Sullivan has now – that Pato ran out of – is time. The Union attacker has the potential play at a professional level for a decade or more.
And the early signs of this 2025 MLS season indicate that Carnell and Philadelphia are taking the patient approach. Sullivan has a long way to go before he's competing at senior team level – but he's on track, and fighting to achieve that level will be crucial.
ImagnHere and now
To start the 2025 MLS campaign, Sullivan has made just one appearance off the bench for the senior team – an eight-minute cameo on Matchday 2 in a 4-1 win over FC Cincinnati, in which he showed glimpses of the excitement that surrounds him.
“Cavan did a good job, just harassing down the left hand side and doing his bit,” Carnell said after the match. “I'm just glad and grateful we could get him a few minutes out there, because he's training really well, and we have to bring him along in the right ways.”
It's evident that – despite his immense talent – there are others ahead of him in the depth chart, including Quinn. On the senior team – again, a talented squad that is currently leading MLS Supporters' Shield standings – Cavan would be competing for minutes at forward with his older brother and the likes of Hungary international Daniel Gazdag, Danish forward Mikael Uhre or current MLS Golden Boot leader and Israeli international, Tai Baribo.
Simply put – there's no space, or reason, for Cavan to be thrown into the XI right now. What is apparent, though, is Carnell is ready to take him under his wing and prepare him for that eventuality.
Carnell, a seasoned MLS veteran himself, has excelled throughout his career with young players on the touchline. He handed U.S. international Caden Clark his professional debut in 2020 as interim head coach of the New York Red Bulls, and prior, he was an assistant coach with Jesse Marsch in 2017 and 2018, where he helped develop current U.S. star Tyler Adams, among countless others.
“I believe I gave Caden Clark his debut against Atlanta away from home as a youngster back then," Carnell said after being named Union manager. "People is the core of my philosophy. Working with people, developing players, this is the core of my philosophy and I feel it’s my duty here it’s, it’s what I do. I’m not here to coach for me, I’m not here to- for sure I enjoy the success that comes with it, but for me when I see players succeeding, this is the most exciting thing to happen.
"When I see a player get promoted through the ranks, as I was once – I was a 16-year-old playing in the Pro ranks in South Africa and somebody gave a chance, somebody gave a shot at me. So I’m all for that and I’m excited about Cavan’s development as well as developing some other youngsters here in camp. I’m excited about that whole process and like I said people are the core of my philosophy.”
For Sullivan, one big change has occurred since Carnell's appointment – involvement. From regular first-team training to inclusion in club activities, he's being looked upon as a Union player, period, not just the next phenom. He's been named to the first-team bench for every match so far this season, and in the three MLS NEXT Pro matches that Union II has played, Sullivan has started each – earning crucial and consistent minutes.
In fact, he's Union II's leading goalscorer on the season with two goals after three straight draws to begin the campaign.
On Matchday 2, his tasteful talent was put on full display as he drilled home an absolutely sensational direct free kick in a 1-1 draw with the New York Red Bulls. It was just the latest clip in his highlight reel, but also a moment in which he was able to boost his confidence and show his squad that he's the rising talent many expect him to be. It's a goal he scores because he's getting minutes at the NEXT Pro level – not just watching from the bench with the senior team.
Minutes with the developmental squad are going to be crucial, but his time with Carnell may be what ultimately defines his season. If he impresses, the 15-year-old could be the latest youngster to flourish under his guidance.
