The Philadelphia Union has signed 14-year-old Cavan Sullivan to the largest homegrown contract in MLS history as part of a deal that will see the American wonderkid join Manchester City when he turns 18.

Mail Sport revealed back in January that City were leading the race to sign Sullivan, widely considered one of the best young prospects in world soccer.

Three months later it emerged that the Premier League giants had sealed an agreement with Philadelphia, where the youngster has played since he was 10, to snap him up in four year's time.

The Union announced on Thursday that Sullivan has penned a professional contract with the team, which includes a clause to take him to Manchester after his 18th birthday.

'I tend not to even listen to what they call me or what they say about me. It's really just what I think of myself,' the young attacking midfielder said. 'I don't really listen to anyone, whether it´s good or bad. So it doesn't really get to me whatsoever.'

Philadelphia Union has signed Cavan Sullivan, 14, to MLS' largest homegrown contract ever

The long-rumored deal - said to be Major League Soccer's richest Homegrown signing ever, although no details were released - allows the Union to continue to develop Sullivan and benefit in the short term from his ability, before profiting when he likely heads overseas to the Premier League. It also allows him to stay at home for a few more years.

While the fee City have agreed to pay is currently unclear, the current record for an outgoing homegrown transfer in MLS was the $20million German team Augsburg spent to sign American striker Ricardo Pepi from FC Dallas in 2022.

The deal is also understood to include significant add-ons, along with a sell-on percentage for Philadelphia. 

Sullivan is considered one of the best young American players. In a match last April between the U.S. under-15 team and England in Spain, he scored both goals in a 2-2 draw that the Americans won in a penalty shootout.

He was named the best player at the CONCACAF under-15 championships. He had a pair of assists in the 4-2 victory over Mexico in the final.

Union coach Jim Curtin recently called Sullivan 'a special talent, top talent not only in this country but in the world.'

Sullivan has already made his professional debut, coming off the bench for the Union's MLS NEXT team last month and getting an assist on the game-winning goal. He's made two appearances for the team, a step below the Union's senior squad.

The teen hopes to make his Union senior debut this year. If he does, he'll join his brother, Quinn, another academy product who has played for the team since 2021.

Sullivan (14 years, 224 days) is the fifth-youngest player to sign a first-team contract in MLS history. If he plays for the Union before July 29, he'll become the youngest player ever to appear in a match. Freddy Adu was 14 years, 306 days old when he debuted for D.C. United in 2004.

'I think Jim Curtin was really integral in getting Cavan here, if I'm being completely honest,' said his dad, Brendan Sullivan. 'He called us, he reached out to us, he said, "Look, I think he can play for me right away. With a little bit of a little bit of coaching, we think that he's ready and we're willing to take that on."'

Sullivan, a Philadelphia native, is the youngest of four brothers. Quinn, 20, is the oldest. Brendan Sullivan played professionally in the A-League, which eventually became the USL First Division, a tier below MLS. His mother, Heike, played at Penn. Grandfather Larry coached at Villanova from 1991-2007.

Sullivan said he first started to get attention by clubs when he was just 10.

'I think that's really when I thought, "This is happening." It didn´t feel real but definitely triggered something in my mind where I was like, "I can do this,"' Sullivan said.

Sullivan can't play for City until he is 18. But he holds a German passport that could allow him to move to Europe and play for City-affiliated teams - like Girona in Spain or Palermo in Italy - when he turns 16.

Because of the collaborative transfer agreement with Manchester City, Sullivan's deal is unusual. It signals that the Premier League club trusts that the Union can develop an elite player.

Sullivan isn't looking too far ahead. In many ways he's a typical teenager, albeit a very gifted one. He jokes: 'I'm a pretty boring kid, to be honest.'

'I mean, you can see him. He's a pretty even-keeled kid,' his mother said. 'He really does that on his own. I'm sure we help keep him grounded, but I think he is already grounded, and I think he should get a lot of credit for that.'