Serbia winger Milan Jovanovic has urged his team-mates to stay true to their "footballing philosophy" at the World Cup despite concerns over their warm-up performances.
Fans caused trouble in Klagenfurt as Raddy Antic's side lost to minnows New Zealand, while a goalless draw with Poland represented only a minor improvement.
The Eagles did manage a 4-3 win over Cameroon but in a group featuring Germany, Ghana and Australia, Serbia know they must regain the form shown during qualification to have an ambitions of making the knockout phase.
Standard Liege attacker Jovanovic, who is set to join Liverpool this summer, has called for calm in the wake of criticism of the team.
"It's paramount that we maintain our peace and stick to our footballing philosophy," he told Blic.
"It's true our performances in pre-World Cup friendlies were not immaculate, but I wouldn't mind if we fared in every World Cup game like in the friendly against Cameroon."