Cassano's inclusion for the match in Warsaw comes a surprise, as the Azzurri boss had thought the Roma striker was not ready yet for full international football.
However, Trapattoni has decided he will take the Italian Under-21 player to face the Poles this week.
Trapattoni will also pick a different squad on Thursday for Sunday's friendly versus Romania in Ancona.
Italy squad for Poland friendly:
Christian Abbiati (Milan), Francesco Toldo (Inter); Fabio Cannavaro (Inter), Matteo Ferrari (Parma), Fabio Grosso (Perugia), Marco Materazzi (Inter), Alessandro Nesta (Milan), Massimo Oddo (Lazio), Giuseppe Pancaro (Milan), Christian Panucci (Roma); Ivan Gennaro Gattuso (Milan), Marco Marchionni (Parma), Simone Perrotta (Chievo), Andrea Pirlo (Milan), Cristiano Zanetti (Inter); Antonio Cassano (Roma), Bernardo Corradi (Lazio), Marco Di Vaio (Juventus), Fabrizio Miccoli (Juventus), Francesco Totti (Roma), Christian Vieri (Inter)
