FIFA spokesman Nicolas Maingot also says South Africa coach Carlos Alberto Parreira will not be sanctioned over negative comments he made about the referee in the 3-0 defeat to Uruguay on Wednesday night.
Cahill received an automatic one-match ban covering Saturday's game against Ghana, but FIFA could have increased the penalty. Maingot said Thursday the one-match ban would stand.
Parreira, meanwhile, said referee Massimo Busacca "was the worst referee so far" after he sent off host nation goalkeeper Itumeleng Khune for tripping Luis Suarez, which led to a penalty. Parreira also said that Busacca "doesn't deserve to be here."