Monaco striker Christian Vieri [Images] and Sampdoria defender Aimo Diana have been ruled out of Italy's [Images] World Cup squad due to injuries, Italy coach Marcello Lippi said on Tuesday.

Vieri is to have surgery on his left knee after suffering an injury during a game against Paris St German in March while Diana has been sidelined with a groin injury.

Lippi will announce his final squad of 23 players on May 15, a week before the squad begins its pre-World Cup training camp.

"I have very clear ideas about my squad and a few injuries have contributed to clarifying the position," Lippi told the Italian news agency ANSA today.

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"Vieri has an operation on his knee and won't be available while Diana has a serious groin injury that won't be right in time and so he won't be able to be called up."

Vieri's absence was expected and allows Lippi an extra place for a striker. Livorno's Cristiano Lucarelli and Udinese's Vincenzo Iaquinta are two forwards in contention as cover for first-choice target man Luca Toni.

Diana, who can also operate on the right side of midfield, could be replaced by Lazio's Massimo Oddo. The finals in Germany [Images] start on June 9.