‘Objective and realistic’ is just code for not believing in him, though. Were you great at 16? Or were you merely good enough to get signed and thus benefit from decades of training and coaching that improved you? Do you not believe he will also improve? That’s literally what not believing in him means. It’s one thing to manage expectations, to encourage him to have a fallback, etc, and quite another to effectively say ‘You’re shit at this so you should just go get a job’ or whatever.