I think we shouldn't have auto subs the way we have it currently. The system should consider the best player to come on in place of an injured player every time. If a player is sent off and the formation becomes illegal, like 3-5-2 with a defender sent off, then the system should pick the worse performing player and sub him off to bring on a defender.

Besides these auto subs, we could then have planned subs, for example, a defender off and striker on in the 70th minute if draw or worse, or vice versa if leading by two goals or more. We could use this to influence the formation, setting the exact position of the player to come on. For Chelsea, starting with 4-5-1V, maybe you'd like Romeu (DMC) off in the 70th minute and Mata (AML/AMC/AMR) on as an AMC in the 70th minute to make a 4-2-3-1 formation.