Galliani believes Stephan El Shaarawy would not have emerged without making room for the youngster over the summer.
"I suffered a lot with Ibra," he said. "The economical situation in this country is what it is. Ibra was a luxury which we had to give up on.
"With Ibra, maybe Stephan El Shaarawy wouldn't have been able to do what he has. I don't have proof of that, but that is what I think.
"Cassano? He continually asked us, via text message, to sell him. He wanted to leave and he's hammered me and Massimiliano Allegri."