The four-time Ballon d'Or winner has scored in all three of Argentina's games at Brazil 2014, but Mehmedi, 23, has vowed not to be in awe of the Barcelona star.
The Freiburg striker has also warned that the South Americans have other players, aside from Messi, who can hurt Switzerland in Sao Paulo.
"With all due respect for his qualities and class, I think too much is talked about just Messi," he told reporters.
"He is exceptional, no question, but that is not all, he has very good players around him. We will not neglect the preparation nor in the game itself."
Argentina are unbeaten in their six previous games against Switzerland, who are ranked sixth in the world.