PHILADELPHIA — Cavan Sullivan has quickly rocketed up the American football ladder.

The Philadelphia Union midfielder already set an MLS age record, became a key contributor for his club, and made his debut for the United States men's national team at 17.

Sullivan's latest milestone arrived Sept. 26 when he started for the United States in a 4-1 friendly win over Peru in Orlando, Fla. It was his first senior international appearance for his country, less than two weeks after his 17th birthday.

The performance was another step on a journey that started when Sullivan was a child in the Philadelphia area and took off when he joined the Union's academy.

From record-breaking debut to senior international

Sullivan first gained attention in July 2024, when he made his MLS debut against the New England Revolution at 14 years and 293 days old.

His debut made him the youngest player to ever debut in MLS, breaking the record set by Freddy Adu in 2004. MLS also pointed out Sullivan’s position as the youngest debutant in any of North America’s major professional sports leagues.

Sullivan signed a Homegrown deal with Philadelphia two months ago, running through 2028, which the club at the time called the biggest Homegrown deal in MLS history.

His contract was also notable for its reported path to Manchester City. According to contemporary reports, Sullivan could move to the Premier League club when he turns 18 under a provision included in the agreement. The move has not yet occurred and should be viewed as a future transfer deal—either reported or agreed, but incomplete.

For now Sullivan remains a Philadelphia Union player.

A breakout 2026 season

The teenager’s development became obvious during the 2026 MLS season.

Sullivan played 24 regular-season games, scoring seven goals and assisting on 12 others in 1,450 minutes. According to MLS, his 19 goal contributions matched Alphonso Davies’ 2018 total for the second-most by a teenager in a single MLS season.

September was especially productive.

Sullivan had nine goal contributions in the month, including four goals and five assists, according to Reuters. That run included a three-assist effort against FC Cincinnati and a two-goal, one-assist showing against San Diego FC.

The form earned him another award, becoming the youngest MLS Player of the Month at 17 years and two days, Sullivan.

His performances also earned him a call-up to the senior national team for the first time.

A multi-functional attacking midfielder

Sullivan is primarily an attacking midfielder but can also play in wider positions.

His game is based on close control, acceleration, and creativity with the ball. He doesn’t just use his physicality but often looks to open space with changes of direction and quick combinations.

Those traits were evident even when he was a student at the academy.

Sullivan joined Philadelphia Union Academy in 2020 and has developed through the club’s system, including appearances for the U-15 and U-17 teams and Union II in MLS NEXT Pro. He also played for the United States at the youth level.

Sullivan helped the U.S. reach the 2023 Concacaf Boys’ Under-15 Championship and claimed the tournament’s Golden Ball after scoring four goals.

He has continued to grow up at the senior level. He scored his first MLS goal against Orlando City in 2026 and had several multi-assist and multi-goal games as his role with Philadelphia grew.

A football family in Philadelphia

Sullivan has grown up in a football family.

His older brother Quinn also plays for the Philadelphia Union, giving the siblings a chance to work together professionally. Cavan’s journey started in the union academy system when he joined at the age of 10.

Prior to joining the Union’s first team, Sullivan also played for the Philadelphia-area youth club FC Delco.

FC Delco general manager Rob Elliot knew the Sullivan family through the club’s youth system and remembered watching Cavan play against older kids when he was a child himself.

Sullivan stood out, Elliot said, not only for his technical chops but also for his approach to competition.

That’s a mentality Sullivan has carried with him as he has quickly moved from youth football to the professional game.

Coming up next

Sullivan’s international debut doesn’t guarantee a permanent spot in the U.S. starting lineup, but it gives him another level of experience at a significant point in his development.

He became one of the youngest ever starters for the U.S. men’s national team in a match against Peru. He was replaced by Zavier Gozo after 62 minutes.

But Sullivan’s 2026 season is already a far cry from what he showed as a 14-year-old rookie for the Union.

The next challenge is to continue that production against more experienced opponents and still develop physically and tactically.

But that progression, not the hype surrounding his potential move to Europe, may be the most important part of the story for a player who entered the professional game unusually early.