"We have to be ready to play really from the get-go in such a way to have the initiative on our side," coach Vladimir Petkovic said Monday through an interpreter.
Switzerland takes on Sweden in St. Petersburg on Tuesday, with the winner facing a quarterfinal against either England or Colombia.
History is beckoning for the No. 6-ranked Swiss team. If it beats Sweden, Switzerland would reach the World Cup quarterfinals for the first time since 1954. The country has never advanced to the final four of the tournament. Sweden's last quarterfinal appearance was in 1994, on its way to the semifinals.
Midfielder Granit Xhaka wants to match Switzerland's best-ever World Cup finish and then surpass it.
"I hope that tomorrow is not our last match and even the next round will not be the final one for us in this tournament," he said.
Against a Sweden team ranked No. 24 in the world, the Swiss team will be without the heart of its defense, with captain Stephan Lichtsteiner and Fabian Schaer suspended after picking up their second yellow cards of the tournament.
"Defensive play will be important tomorrow (Tuesday)," Petkovic said. He wouldn't confirm who would replace the suspended defenders, but Michael Lang and Johan Djourou are expected to be named in the starting line-up.
If the defensive play leads to a repeat of the way Sunday night's two last-16 matches ended — in a penalty shootout — Xhaka is ready to step up to the spot. That is despite his missed penalty in a shootout two years ago allowed Poland to advance to the European Championship quarterfinals at the expense of Switzerland.
Xhaka said he hopes the match is settled in regulation or extra time, but if it goes to another shootout, "I'll be happy to assume that responsibility. Whether or not the coach will allow me to do that is an entirely different question."