Bury were relegated on Saturday from League One with four games remaining having lost to fellow strugglers Northampton Town.
Butler believes it is difficult to predict just what the Shakers will do in tonight's rearranged fixture.
But he insists Rovers will not underestimate Ryan Lowe's side.
"I'm not quite sure what to expect to be honest," Butler said.
"It can go a few ways. Are they a wounded animal? Will they think it's time to blood some youngsters?
"Are they playing for contracts?
"Is it a case of pressure being off? I'm not sure.
"We're not going to take it lightly. We'll approach it like every other game because that's what we've done with every game this season.
"It's not going to change because one team has got a little R next to their name.
"We were in that situation where we're down there a couple of years ago.
"You still fight for every point because you've got to prove yourself as a player.
"If you're not prepared to prove yourself there's no point playing football.
"I'm sure their gaffer will have them right up for it and we've got to be at our best to beat them."