I have had him sub out numerous of times when only fielding 9 players and no blank slots. Happens in the last two minutes in the game when you get a FT and your winning by a lot.
With strictly follow and risk for foul trouble and putting a trainee as starter, backup and reserve I can think of only 2 scenarios when my trainee won't get 48 mins - if he's fouled out or injured. And of course, you can't have blank positions in the lineup. That's important. I've never experienced anything else with this setup. And Manon, this is regardless of my roster and how the game goes.