The Clarets lie four points adrift of the play-off places but have two games in hand on sixth-placed Leeds.
Victory against the lowly Eagles would maintain their fine run of form under boss Eddie Howe but Marney is wary of the Londoners' threat at Turf Moor on Saturday.
He said: "They are fighting for their lives and they're not doing their best away from home but they've got good players so if we don't go out there in the right frame of mind then it could be a bit of an upset.
"But I'm sure the way we've prepared for the game and the the way the gaffer talks to us we'll do the business."
Source: PA
