Cassano is currently recovering from a minor heart operation, while the Villarreal striker recently underwent knee ligament surgery. Both could be sidelined for six months.
"I went to see Cassano and he told me that he'd like to say hello to everybody," said Prandelli.
"He is calm and motivated to return. I just wanted to say that we miss him. We noticed today that there is a different atmosphere without him.
"Antonio really feels for the Azzurri shirt. We'll follow his recovery closely, even before he returns to action. We all hope to have him ready for Euro 2012.
"Rossi's situation is different to Cassano," the tactician added. "If Giuseppe is in good shape before the championship then he'll be there, otherwise we'll have to develop play in another way.
"I don't want to give any reference points to our opposition and that is why I haven't called up any pure centre-forwards."