Joachim Low's men take on the United States in their final Group G fixture in Recife on Thursday, with qualification for the last 16 still not assured.
A draw would see both sides through to the knockout stage, with Germany as group winners, and even a defeat for Low's side may not mean elimination, due to their goal difference being superior to both Portugal and Ghana.
However, Muller, who is set to be available despite suffering a nasty looking facial injury in the final moments of Saturday's 2-2 draw with Ghana, wants his team-mates to push on and seal top spot.
"I do not have a physical problem," he said in a press conference on Tuesday.
"We want to finish top of the group.
"Six goals in two games is not bad. We could have scored more against Ghana and also against Portugal.
"We still always want more and more.
"Joachim Low has left his mark on this team. The most important thing is we walk step by step, one game at a time."
