Bayern Munich midfielder Xherdan Shaqiri claimed a hat-trick in Wednesday's 3-0 win over Honduras as Switzerland finished second in Group E to book their berth in Sao Paulo against Lionel Messi's Argentina.
   
The Swiss had to pick themselves up to beat Honduras after their 5-2 hammering to France in their second group game.
   
Schär says the relief at making the knock-out stages was palpable in the Swiss squad, who now have nothing to lose against Argentina.
   
"We have reached our main goal and we can now play without pressure," said the 22-year-old FC Basel defender, whose unenviable job will be to contain Messi on Tuesday.
   
"We are clearly the underdogs against Argentina and we want to use the opportunity."
   
The teams are evenly matched on paper with Argentina ranked fifth in the world, just one ahead of the Swiss, and Schär insists they will not be travelling to Sao Paulo to make up the numbers.
   
"We know we have the quality to challenge them," he said.
   
"It's great for us that we can compare ourselves to one of the best teams in the world and Lionel Messi is one of the world's best players.
   
"It was a must for us to reach the knock-out phase and it wasn't a given before our matches.
   
"We have reached our main goal, so now whatever comes is a bonus."