Italy midfielder Daniele De Rossi has sent a letter to Fifa's disciplinary committee explaining his elbow on USA striker Brian McBride.
De Rossi was sent off for his actions in Saturday's 1-1 draw and will definitely miss Italy's last Group E game against the Czech Republic.
In the letter, he took responsibility for his error and explained how he apologised to McBride after the game.
Fifa will decide by Friday whether he will be banned for another three games.
"I've left De Rossi to boil in his own soup. He's a fantastic guy but he must change his computer chip," said coach Marcello Lippi.
Fifa will also consider Uruguayan referee Jorge Larrionda's report on the incident and TV replays.
Italy are braced to accept any punishment Fifa may hand down to the youngest player in their squad for his role in a stormy match which also saw two USA players dismissed.
That is in contrast to the 2004 European Championship, when the Italians hired a lawyer to fight a three-match ban imposed on Francesco Totti for spitting at an opponent.
"Italian players have these habits and they have a tough time at international level."
De Rossi could be in trouble with Italy coach Marcello Lippi as well as Fifa following the dismissal.
He was yellow-carded in Italy's opening win over Ghana and Lippi said: "He's got to think things over for a while and not only about last night.
"Then I'll talk with him, unfortunately, I think I have plenty of time.
"Italian players have these habits and they have a tough time at international level."
Giancarlo Abete, head of the Italian delegation, said: "It was a serious incident but it's not an episode that can represent all of Italian football.
"Obviously it was a negative incident but it should be kept in context."
Italy were left to count the cost of a bruising encounter, with midfielder Simone Perrotta listed as doubtful for the crucial final Group E match against the Czech Republic.
Perrotta suffered a leg injury but had to finish the game as Italy had used all their substitutes.