If you are blowing a team out, then in the 4th quarter all of your back up players will come in. If you have a player set as Starter, Backup and Reserve then it "should" not happen.
Assuming that every other player active for the game is set to be either the backup or starter at another position, at least. Any players active but not on your depth chart will also come in if there is a starter who is not otherwise replaced. The easiest way to describe how to set up a lineup for the maximum chance of 48 minutes for a position is:
1-1-1
2-6-6
3-7-7
4-8-8
5-9-9
With only 9 players available for he game.