Cassano was unimpressed by Tottenham's defeat at Arsenal on Sunday.
He told Calciomercato: “No one can say that Mourinho's teams have played and play well.
"Yet Mourinho has won two Champions Leagues, a genius like Cruyff has only won one. But we can't compare Cruyff to Mourinho in the least.
“Mourinho's football will never go down in history, I speak personally by saying that he doesn't excite me.
"Tottenham have an impressive squad but have been defending the whole game except for the last 10 minutes. I can't think that a coach who has won so much can go on like this."