So I know that substitutions happen fairly regularly and realistically for NFL standards, but I'd like it if you could set up your own substitutions for specific positions, or maybe at least the running backs. For instance, the Dallas Cowboys aren't opposed to giving one guy 30 touches per game, while the Bengals like to split it up fairly evenly. Also, maybe you want to get that sixth WR rotated into the game more often.

Currently there is no way to control subs based upon position.

The only way would be evenly planning your game plan and adjust your starters for each formation.

You can try to get individual players into or out of the game through situational substitutions using overrides on the depth chart. You can further hone substitution patterns by only calling certain formations (i.e., plays) in certain situations using rules. It takes a bit of work, but can be useful. And can be applied on both offense and defense.

For example, let's say you have a player who is very good at rushing the passer but poor against the run. Using the depth chart, you can substitute him in on 3rd or 4th down and long distance situations, but otherwise use him minimally (other than through him substituting because a starter is fatigued or injured). And you can choose to substitute him only on nickel and dime formations if that's your preference.