The Swiss side face the host nation's South American rivals in Sao Paulo on Tuesday for a place in the quarter-finals.
The goalkeeper said at a press conference: "We will have the support of the Brazilian fans in the stadium. One can feel the rivalry between Brazil and Argentina. It would be nice if it were a Swiss home game.
"We're preparing for [Lionel Messi] as we would any other player. But it is also clear that it will be difficult to take Messi out of the game completely. You can watch as many videos of Messi but when he makes something surprising at the crucial moment, it will have been to no avail."
Xherdan Shaqiri scored the second hat-trick of the tournament against Honduras earlier this week to book Switzerland's place in the knockout stages.