Cassano has now been given the green light to resume his competitive career following heart surgery last November.
"Antonio is as happy as a child," representative Beppe Bozzo told TMW on Wednesday.
"He's been through some delicate times, with thousands of thoughts, questions and reflections.
"A lot of people stayed close to him, as all of the Milan family did. Things may have been different at another club.
"He has a great desire to get back at the disposal of Milan, a club who cured him and allowed him a new life - on and off the field."