Italy coach Cesare Prandelli will reveal a pre-squad of 30 players for Euro 2012 on Sunday, the final day of the Serie A season, the Italian Football Federation (FIGC) told AFP on Thursday.
The squad will have their first training session next Monday at Coverciano near Florence and will then be whittled down to 23 on May 29.
Internationals playing for Juventus and Napoli, who will take part in the Italian Cup final on May 20, will remain at the disposal of their clubs.
Prandelli has already indicated there will "no enormous surprise" amid speculation of possible returns for Francesco Totti or Alessandro Del Piero.
However, temperamental Manchester City forward Mario Balotelli is expected to feature, along with AC Milan striker Antonio Cassano, who has returned from heart surgery.
Italy are in Group C at the European Championship, being co-hosted by Poland and Ukraine, along with defending champions Spain, Republic of Ireland and Croatia.
The Italians play two friendlies before Euro 2012, against Luxembourg on May 29 in Parma and on June 1 against Russia in Zurich, Switzerland.
The team will leave for their training base on June 5 in Krakow, and will visit Nazi Germany's Auschwitz death camp in Oswiecim, southern Poland, the following day.