AC Milan Chief Executive Adriano Galliani, whose side host Palermo on Saturday, said that he was unworried by the situation, although the Italian Footballers Association (AIC) says it is time to help players confront the problem.
Cassano, 29, who scored twice for Italy in a 3-0 win over Northern Ireland on Tuesday, told RAI television that he had already made retirement plans.
"I'll play for another three or three-and-a-half years," he said. "I want to have a good Euro , a good World Cup and a regular place for the national team.
"I've been involved with the national side for 10 years and have only 25 caps, I'm always in and out of the team. I'll quit at 32 or 33 at the latest, I'll get out of football and enjoy life with my family.
"Football has been the most beautiful thing in the world for me but despite that, I'm exhausted. I'm stressed, for the last 13 years, whatever I say has been wrong."
Last week, Sweden forward Ibrahimovic said that he had started to think about retirement, when he said he would be able to enjoy life.
He also complained he was tired and not enjoying the game as much as before.
AIC President Damiano Tommassi told the ANSA news agency said the problem needed to be confronted.
"It's one of our objectives," he said. "We have started a project to help players, from 17 years onwards, to deal with pressure.
"They are boys and there toughest game is to be themselves and not have to put on a mask."
Galliani said he was confident the pair's form would not be affected.
"I'm not worried," he told reporters. "I'm not a psychologist, but I speak to the players in private and everything is fine.
"After 25 years of management at Milan, I known how to do it. I've spoken to Ibrahimovic, he absolutely wants to play. There's nothing else to comment.
Milan, a modest 15th in the table after taking only five points from five games, have been hit by injuries this season but should at least have Brazil forward Robinho fit again for Saturday.
"I'm fine, happy and recovered," the former Santos, Real Madrid and Manchester City forward told reporters.
Leading pair Juventus and Udinese, who have 11 points each and are the only unbeaten sides, are both away, Juventus visiting Chievo and Udinese at Atalanta.
Struggling Inter Milan, who have only four points, travel to Catania for a Saturday game.
The Lazio-AS Roma derby on Sunday will round off the weekend. Roma captain Francesco Totti is out of the game with a thigh strain and Lazio's Germany striker Miroslav Klose is doubtful with a knee injury.
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