Johan Djourou believes "anything is possible" as Switzerland prepare to face Brazil in World Cup opener.
Brazil are among the pre-tournament favourites, having fallen in spectacular fashion on home soil against Germany in the semi-finals four years ago.
Serbia and Costa Rica - the latter were quarter-finalists in 2014 - fill out a competitive Group E, but Djourou feels Switzerland can qualify for the knockout rounds in Russia.
The Antalyaspor defender, though, accepts the calibre of opponent Switzerland face against Brazil on Sunday makes their opening task difficult.
"I think that when you play a World Cup you can only be excited," Djourou told Omnisport.
"That's one of the best things that can happen to a football player, is to play for your country in a World Cup.
"I think Switzerland have done very well in the past. I think we have a tough group. I think that Brazil, Serbia and Costa Rica is not easy.
"I think that the first game always will set the tone because the first game in a competition is always very important and we play against Brazil, against a great team with great individuals like Neymar, [Philippe] Coutinho, Thiago Silva and many, many players.
"I think it's down to us. We have to prepare well this tournament and give our best because I think Switzerland progressed as well a lot. But we know that we play against one the best teams in the world, but in football anything is possible."