Crouch was reportedly upset about being left out of Saturday's defeat of Aston Villa, but Benitez said: "I have prepared the same speech for all the players.
Until there is a fundamental change in the rules, he joked, he will be sticking to his guns.
"Sadly, I have been unable to persuade FIFA, UEFA, and the Premier League to allow me to use 12 players in every game!" he said.
"I can only use 11 - and I cannot have more than 18 players in a squad for a European match.
"Every player knows they have team-mates to consider. They are professionals and they need to be ready for each game. I will always have the same answer."
Benitez denied his policy has caused any significant unrest to date. "I have heard that there are some problems with Crouch - that is not the case," he said.
"The same applies to Pennant, and for the likes of Javier Mascherano and the rest. It is the same answer for everyone. I now hope I do not have to repeat this to the media every week. The players know they are professionals, and this is football."