Harry Kewell could miss Australia’s final Group F game against Croatia after being charged by Fifa after he insulted the referee Markus Merk.
The Liverpool winger was reported for swearing at the German official after Australia’s 2-0 defeat to Brazil on Sunday.
Kewell has until Tuesday to respond and the verdict will be announced before the final group game on Thursday.
Fifa communications director Markus Siegler said: “Fifa have opened disciplinary procedures against Harry Kewell.
“It was reported in the referee’s report that he insulted the referee several times.”
Kewell later said his behaviour was in the “heat of the moment”.
“You’re frustrated, you’re losing the game, every referee puts up with it,” said Kewell.
“I mean, it’s part and parcel of the game. He knows there’s no harm meant by it.
“You go out there and play so well against the world champions and you come off losing, whereas you think you should have come off with something. He understands that, that’s the way it is.
“It was a hard match to referee, and he did a good job.”