Hello,
I started a save with Boston United (Vanarama North), which doesn't have a reserve squad at the beginning. At the start you get the option to ask the board for a under-23 squad, which I did, but it got rejected. Now, more than a season later I still don't have a under-23 squad and I never had the option again to ask the board for it (I checked regularly if the option popped-up at the ask the board menu).
So the question is, will the option ever come back to ask the board for the under-23 squad or will they give you one at a certain point in the game (f.e. when you get promote
