Portugal forward Joao Pinto could face a serious sanction from world governing body FIFA who have television evidence that he punched Argentine referee Angel Sanchez after being sent off in Friday's clash with South Korea.
FIFA communications director Keith Cooper said the report of the referees inspector on the incident had been submitted to the body's disciplinary committee, which was due to meet on Sunday.
He said a special hearing with the referee would take place on Wednesday in Tokyo.
Portugal's captain Fernando Couto also held Sanchez by the face as the players argued with the referee in the protests that could even have an impact on the availability of Joao Pinto and Couto for the 2004 European championship that Portugal hosts.
Cooper declined to say whether the report included allegations of punching.
But FIFA sources said the ruling body had television pictures of the incident on the pitch and photographs were taken of the bruise on Sanchez's body that the referee alleges was caused by Joao Pinto's punch.
"He punched me on the left, in the ribs," Sanchez told Portuguese state radio on Saturday in an interview.
Joao Pinto was sent off in the 27th minute of the 1-0 group D defeat by South Korea that put Portugal out of the World Cup. He was dismissed after a tackle from behind on Park Ji-sung.
Portugal also had Beto Severo sent off after a second yellow card following a late challenge.
Cooper declined to speculate on what action the disciplinary committee would take.
But Portugal defender Abel Xavier was banned for nine months for manhandling a referee in protest after they went out of the European championship in the semi-finals against France two years ago through a golden goal. The ban was later reduced on appeal.
"The general rule is that the referee should not be touched," Cooper said. "Players always run the risk by laying hands on the referee. The wisest thing is: 'Hands Off'."
If FIFA decides to impose international match bans on Joao Pinto or Couto, they will not come into force until the first-round group games of the Euro 2004 finals.
Friendlies do not count for match ban purposes. Portugal, who do not need to qualify for the tournament as hosts, will not play a competitive match until the finals.
"This incident has been contained in the report of the referees inspector. As those documents go to the disciplinary committee it is in their discretion about what action to take, if any," Cooper said.
"All I can say at this point is that I'm taken by surprise that the referee spoke openly about the incident to the press before it had been dealt with by the disciplinary committee."
Sanchez said in the radio interview that former Portuguese great Eusebio approached him after the game to apologise on Joao Pinto's behalf.