Seasoned Italian coach Fabio Capello said Cassano had failed to make the most of his talent and did not know the limits while Inter club president Massimo Moratti described the player as an artist who was a "bit special."
Cassano's latest row with Inter coach Andrea Stramaccioni added to the long list of explosive episodes which have marked his career.
Former AC Milan, Juventus, AS Roma, Real Madrid and England coach Capello said Cassano had to learn to accept other people's decisions.
"He's a very good lad, generous and with great talent, but he doesn't know the limits of respect and education," the Russia coach told RAI radio.
"He sees football in a certain way and only knows that way, and because of that, he loses the respect of his team-mates.
"I hoped that after the birth of his son, he would calm down.
"He has to understand that there are moments when you have to accept other people's decisions.
"It's a shame because the lad has plenty of talent and he could have done a lot more."
Born in Bari, Cassano has had a long history of spats and personal clashes.
He led Italy's attack at Euro 2012 alongside Mario Balotelli but, although they reached the final, Cassano was also remembered for saying that he hoped there were no homosexuals in the team.
Asked at a news conference to comment on reports that there were two "secret" gays in the Italy squad, he said: "That's their problem. I hope there isn't one in the national team."
After criticism from gay rights' groups, Cassano issued an apology through Italian state news agency ANSA. He was fined 15,000 euros by UEFA for a "discriminatory press statement".
Moratti said that Inter, fourth in Serie A and back in the hunt for a Champions League place, were returning to normal after the incident at the weekend.
"I wasn't there, so I can't tell you what happened. But I see everyone is getting back to normal," he told Inter's website.
"He's a talent, as we know, and artists are a bit special. Basically we need to understand him.
"I see everyone is scandalised that it's been leaked, but what's worse is that it's gone on in the first place, not whether it's come out or not.
"There are 40 people in the dressing room so of course it can come out. It's a shame but obviously these things can happen. Ultimately these things mustn't happen though."
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