The Germany goalkeeper, whose nation has also been drawn against the USA and Ghana, says that "the first match is the first final."
Joachim Low's side began the 2010 World Cup in convincing fashion with a 4-0 win over Australia.
That set the tone for its campaign, which ultimately saw it finish third and was highlighted by its dismantling of England and Argentina in the knockout stages.
A similarly fast start is crucial, according to Neuer, who will be tasked with keeping out the likes of FIFA Ballon d'Or winner Cristiano Ronaldo in the clash.
Neuer told Bayern's official website: "I think it's important to make a good start, hopefully with a win. It gives us power for the games to come. The first match is the first final, everything's on the line. Football is the main sport in our nation, so the expectations are high. We aim to fulfil those expectations."
After Portugal, Germany will face Ghana and the United States in Group G at the World Cup.