So the rules i put with the game describe what i call blind substitutions.
This is where when you want to get rid of a bad card in your hand you replace it with the top card of the subs bench hoping that it's better than the one you removed.
Advanced substitution rules
When you take the 15 Bench cards out at the setup phase. Look through the cards and select the three cards that you will want to bring back into the game during the match. Put them at the top (or front) of the bench so you can access them when needed during a match.
This also allows you to have a look at the cards you won't be playing with and if you want a bit of a competitive edge it is helpful to see what sort of form your team might have in the game and adjust your tactics accordingly.
Let me know how this plays?