Mattia De Sciglio has been ruled out of Italy's World Cup opener against England with a calf strain.
The AC Milan left-back pulled up during training on Thursday before undergoing an MRI scan to assess the extent of the damage.
"Defender Mattia De Sciglio, after [Thursday's] training session in Portobello, has sustained a muscle strain in his left thigh," said team doctor Enrico Castellacci.
"The player underwent this afternoon an MRI at Angra dos Reis and the test has revealed an oedema in his left femoral biceps. De Sciglio will not be available for the first game against England."
In more positive news for the Azzurri, right-back Marco Verratti has returned to full training after being sidelined for two days with flu.
The news comes after defender Andrea Barzagli expressed concern over Italy's defence ahead of Saturday's game against England, urging caution in set-piece situations.
"In recent times, we have given away more goals than we wanted," he said. "But the important thing is to give solidity to our defence," he told reporters.
"Against England, we will have to be very careful on dead-ball situations. They are very dangerous in the area and these are important details where we must not make mistakes.
"I hope our strikers can test England's defence. They have a tough defence and we have tried several options to make life difficult for them."