Hello mate
If you are like me in building a team stage and dont care taking a little bit off risk and perhaps loosing a game or two, you can always force your player to play 48 minutes a game, by not putting a backup player in your team for your trainees.
Only in very rare cases, will backup players for other positions come into the game for your PG. I am training SG and PG and that way I can train quite succesfully 6 players a week.
Hope this makes sense and it helps...