The 30-year-old has been in fine form since joining the Nerazzurri in the summer from rivals AC Milan, but wasn't picked by Cesare Prandelli for the Azzurri's matches with Armenia and Denmark.
Cassano still insists that he wants to be considered for the national team.
"I don't know why I wasn't called up but I hope to be taken into consideration all the way until the end for the World Cup," said Cassano.
"The thing I find a bit irritating is that the journalists find out who gets called to the squad even before the players do."
Cassano has scored four goals in six games for Inter.