The news of Barzagli's absence is another blow to coach Roberto Donadoni following the loss of captain Fabio Cannavaro before a ball was kicked this summer.
"The Euros are over for Andrea Barzagli," confirmed a team spokesman.
"The defender, injured in training, immediately underwent checks which showed a tear in the meniscus of the left knee.
"The player has expressed a desire to stay with the squad but in the coming days he will have an operation."