Who's going to ruin anyone's career? We just signed two lads from Spain, they were Instgramming it, the club confirmed it, they flew to Manchester and no one really gave a shit.
If you want to talk about ruining someone's career, let them sign for United at the age of 18 and then tell them that for the next year they're not allowed to tell anyone about it otherwise the deal is off. On top of that, if their friends or family let it slip, that counts too.
No one's going to care what this kid does until he puts a United kit on anyway.