Italy defender Alessandro Nesta is highly doubtful for his team's final group G game against Mexico, team doctor Andrea Ferretti said.
Nesta suffered an injury to the sole of his foot during his team's 2-1 defeat to Croatia on Saturday.
"We will do all we can to get him fit for Mexico but in my experience it is difficult," said Ferretti.
Ferretti said that Nesta had suffered bad bruising to the sole of his foot but ruled out any fracture.
The central defender was sorely missed after leaving the field in the 24th minute with the score goalless.
Nesta was angry with English referee Graham Poll after suffering what he said was a "sharp pain" in his foot.
"I asked the referee four times to stop the game and he did nothing. What do I have to do? Make a scene?"
Italy's final group match against Mexico will be a make-or-break affair following their surprise defeat and coach Giovanni Trapattoni will be keen to have Nesta avaliable.
Should Nesta fail to be fit Marco Materazzi, who replaced him against Croatia, is the most likely deputy.