The AC Milan forward scored a brace in the 3-0 UEFA EURO 2012 Group C qualifying victory against Northern Ireland but then dropped a bombshell about his future.
"I'm 29 and I've been in the national team for 10 years but I've only got 25 caps," he said. "I'm always in and out, I'm stressed. I want to have a good Euros, a good World Cup and then I'll retire.
"I'll stop at 33, I want to quit when I'm still good. I'm stressed, for the last 13 years whatever I say is wrong. So at 33 I'll leave football and enjoy my family.
"I hope to have two or three children (he currently has one). Football has been the best thing in the world for me but now I'm a bit tired. I'm tired of the routine, I want to have three more good years and then that's it."
Cassano also admitted, perhaps ironically, that he hadn't deserved much success and that's why he hasn't had much, although he was part of AC Milan's title winning side last season.
"If someone wins little they deserve that and if they win a lot they deserve that," he told Rai Sport. "If Gigi (Gianluigi Buffon) has won a lot it's because he deserved it, I've not given a lot so I haven't won much.
"Even so I must thank (Italy coach Cesare) Prandelli who has shown confidence in me and was close to me when everyone was telling me I was fat. We have a special relationship, we talk on the phone a lot and he gave me the platform to do well with Milan."
As for his future after football, Cassano jokingly aimed a dig at his detractors. "I don't know how to do anything, not even speak so I couldn't be an expert summariser because I only say stupid things," he added. "Seventy per cent of (his stress) is my fault, I've always looked for trouble.
"But even when I do something good 30 per cent of the time, I get criticised by journalists. I'm leaving, but don't worry you'll still have a lot to write because there's still (Mario) Balotelli."
Cassano also reacted angrily to a question about him equalling Francesco Totti's nine goals for his country. Cassano and Totti famously didn't get on when the pair played for Roma together from 2001 to 2006 before Cassano moved to Real Madrid.
"It's normal that I wanted to score the goals otherwise I would have shot wide," said Cassano. "Every so often it would be nice to be praised otherwise I'm always getting massacred, as for the rest I've been a clown since birth."