Serbia midfielder Nemanja Matic has said that his side "must respect" Switzerland ahead of the clash between the teams on Friday evening.
Mladen Krstajic's charges, who defeated Costa Rica 1-0 last Sunday, can book their place in the knockout stages of the World Cup with victory over the Swiss.
Manchester United midfielder Matic told the Daily Mail, however that the Swiss - who held five-time champions Brazil to a 1-1 draw in their first game - must not be underestimated.
"Of course we are aware of the fact that if we win we will have progressed from the group and of course we will do our best for that to happen but you know we are facing a very good team," the 29-year-old said.
"The Swiss team will also try to be a threat to win three points. They have a lot of quality and we respect them. They have qualities throughout their squad, excellent individual players and team spirit.
"We expect a hellish game but we are going to be ready for anything."
Matic has scored two goals in 41 appearances for his country since making his debut in 2008.
