Switzerland are sweating on the fitness of star striker Alexander Frei following an incident at training that forced him off the pitch.
Frei was injured in a tackle by Steve von Bergen and may not be able to board the flight from Switzerland to South Africa.
Head coach Ottmar Hitzfeld said he was remaining positive about the fate of the nation's all-time leading goalscorer.
"I hope he has not torn any ligaments or fractured anything," Hitzfeld said. "We have sent Alex to hospital to get a clear diagnosis.
"At the moment, I presume that he will be able to fly with us. You have always got to think positively. Although he had a lot of pain, we have got to hope that he can play in the tournament, even if he cannot play in the opening game."