There's a couple of things here, every player will back themselves to achieve, they've all beaten the odds just getting to be professionals.
Secondly, we're going to be a Championship club next season who, most probably, won't give him a chance and the best he can really hope is he gets a loan at L1 or L2 level which is likely to be available to him at Man City.
Man City don't necessarily see him as ever being in their 1st XI but more a Harwood-Bellis/James Trafford sort where they can sell him, along with a couple of others, for £15-20m each, and buy a played to slot straight in to their first team.
My prediction is, by the time he's 21, he'll be at a Crystal Palace type club.