@LessStressThanFifa No my friend , don't worry about the bench. What matters most is your first 11 line up.
And be careful with how you will choose your special tactics... If you have a very strict Ref , choose wisely your tackling and pressure etc. You cannot afford to lose another player tonight, from what you wrote here. ;)
"I'm top of the league and closing in on 25 wins in a row between my two careers, to get the achievement so I'll be annoyed if it counts as a straight loss."
Congrats for that , but keep in mind that for this achievement you will need 25 wins in a row from a single league / Slot mate ( including Cup matches ). And not by counting wins from multiple leagues. If it was like that it would be so easy for an achievement .
P.S. Do you have maybe a spare midfielder to place on your bench? Not the ideal thing to place our players out of their rightful positions ...but extreme situations require extreme measures sometimes.