Sampdoria striker Antonio Cassano could miss Italy's opening European Championship qualifiers with a back problem.
The 28-year-old, who has 16 caps for his country, returned to the international set-up in a friendly with Ivory Coast last month after a two-year exile.
New coach Cesare Prandelli sees the Sampdoria forward as key to his plans for the 2012 qualifiers, but he faces a race against time to be fit for Friday's visit to Estonia.
The former Real Madrid player underwent tests in Genoa on Monday and will link up with his team-mates in Coverciano, near Florence, on Tuesday.
"The player's back seized up and he was unable to move today [Monday]," said team doctor Enrico Castellacci
"Tomorrow he will be at Coverciano, we'll take a look at him and evaluate the tests conducted in Genoa."
Meanwhile, Juventus midfielder Claudio Marchisio has been ruled out of the Estonia game as well as next Tuesday's visit of Faroe Islands and has been replaced by uncapped Sevilla loanee Luca Cigarini.
"An initial prognosis suggests he'll be out for 10 days, hence Marchisio will miss the trip to Estonia and the match against the Faroe Islands," said a statement from the Italian Football Federation.