The out-of-favour Sampdoria player's transfer to AC Milan will be completed on January 2.
A smiling and visably moved Cassano was already wearing his new team's training kit as he was greated by a crowd of fans at Milan airport before the team jetted out for the Middle East.
His contract will not be filed before the official opening of the transfer market on January 2, but agreement has been reached allowing the player to join his new team's training camp in Dubai.
"We're expecting a lot from him, he's a bonus to the team," said AC Milan defender Massimo Oddo.
"We hope that everything will go well. Milan offers a favourable environment because they give you everything but they demand respect. We'll also be keeping an eye on him."
Cassano, 28, joined Sampdoria from Real Madrid in 2007. But he was frozen out of the club after insulting president Riccardo Garrone during an argument in October.
Sampdoria had applied to have his contract unilaterally terminated for gross misconduct.
An Italian league arbitration board ruled that his salary should be cut by 50 percent, but that his contract could not be cancelled.
The former Roma star has attracted controversy throughout his career for on-pitch tantrums and disputes off it with coaches, presidents and team-mates.
The five-million euro clause due to Real Madrid, Cassano's club from 2006-2007, which had been holding up the deal, will be jointly paid by Sampdoria, AC Milan and the player himself, according to Gazzetta dello sport.