Torn ACLs are not career killers anymore, as long as he doesn't try to come back too early.
Just saw Marca reported it is indeed a torn ACL.
An ACL tear at this early age can change your career trajectory.
It doesnt mean its for the worse but it will change what kind of player he is to an extent. It may end up that he becomes less aggressive and headless chicken and focuses more on football. And his injury heals well and they manage to stabilise his reformed ACL.
Or it could be a very bad tear and get constantly reinjured. And he loses athletic ability and adds nothing.
We really don't know yet but it could be very bad or not matter much.