Madrid will be looking to the fans to help create an inspiring atmosphere, so Subotic believes that it is important for the Germans to hush the parochial Spanish supporters.
"We will try to continue bringing our positive attitude to the pitch in the Champions League," Subotic told ESPN.
"However, we know that our three-goal advantage doesn't guarantee us anything yet. We know that Madrid will appear a lot stronger at home than they did in Dortmund last week."
Dortmund travel to Madrid in the return leg on Tuesday night.