Prandelli has to revamp his squad for the tournament, as first choice strikers Giuseppe Rossi and Cassano race against time to recover from knee and heart surgery respectively.
"I have told both that I'm ready to wait for them until the last minute of the last day," Prandelli told Sky Sport Italia.
"I will go to Spain to check up on Pepito's progress. I spoke for a long time with Antonio and we exchanged more than a few promises.
"We haven't even ruled out that he could come as our 24th man, seeing as he made such a decisive contribution to our qualification."