What did he sign age 15 or whatever that would stand up in a court of law?
This is where I make the same comment every time this comes up:
It is immoral to “sell” an underage minor. It is often illegal. It was wrong with Phonzie, and it would be here.
If the kid wants to play for Arsenal, or whomever, best of luck to him. If the team he goes to will pay for the privilege, it should ALL go to him and his family.