The Udinese man has been preferred to the enigmatic 21-year-old striker, who has paid the price for failing to net in either of his two starts to date, against Spain and Croatia
The Udinese striker, who netted in the Azzurri's tournament opener against Spain, will make his first start after being paired with Antonio Cassano up front.
Elsewhere, the expected switch in formation from 3-5-2 to 4-3-1-2 sees Daniele De Rossi return in midfield alongside Andrea Pirlo and Claudio Marchisio, with Thiago Motta moved forward into the trequartista role.
Federico Balzaretti takes over from Emanuele Giaccherini on the left-hand side of the defence, Christian Maggio makes way for Ignazio Abate on the opposite flank, while Giorgio Chiellini has been paired with fit-again Juventus team-mate Andrea Barzagli in the centre.
Italy must defeat the Irish and hope that qualification rivals Spain and Croatia do not draw 2-2 or higher in Gdansk if they are to progress to the last eight.
Italy (4-3-1-2): Buffon; Abate, Barzagli, Chiellini, Balzaretti; De Rossi, Pirlo, Marchisio; Motta; Cassano, Di Natale.