Subject: conditional orders for red cards

How do I set up a conditional order(s) to take a striker off and bring on a defender if any of 3 defensive players get red carded?

Also if a player gets slightly injured and I set the rule to 'first from the bench' will it always pick the first sub with the same orders e.g. DEF, if one is available, or just the first sub?
(edited)

I'm not sure you can do this.

What you can do is use "if red card or no player" for each defender - and substitute with a player that is already on the pitch - mabe a defensive mid.

you can do as forestman suggests, then replace defensive mid position with attacking mid and then attacking mid with striker. that way you cover the defence and lose a striker position rather than mid