Key Italian central defender Andrea Barzagli is a major doubt for Euro 2012 after tearing his left calf muscle according to the team doctor.
The 31-year-old Juventus star - a member of Italy's 2006 World Cup winning squad - will definitely be out for around 20 days according to the doctor Enrico Castellacci.
"We will do our utmost so that he recovers in time, but that will be tough," said Castellaci.
"What is for certain is that he will not be available for the group stage matches."
Barzagli, a title winner with VfL Wolfsburg in 2009 and then with Juventus in Serie A last term, will undergo further scans on Friday which will then give coach Cesare Prandelli a clearer idea as to whether he should replace him or not.
The injury to Barzagli is a major blow to Prandelli's plan to play three central defenders just as Juventus did last season.
For Italy's opening group game against holders Spain next Sunday in Gdansk Prandelli could well opt to play Angelo Ogbonna, who had an outstanding season for Torino last season which saw them promoted to Serie A, in place of Barzagli.
Should Barzagli be ruled out for the tournament then Prandelli is likely to call up Inter Milan's Andrea Ranocchia, who made the final 25 but failed to make the final 23-man squad.