MILAN - AC Milan and Italy forward Antonio Cassano issued an open letter to his well-wishers on Monday, saying their support had cheered him up suffering an illness which will sideline him for several months.

The 29-year-old underwent minor heart surgery last Friday after falling ill on the plane back from a match at AS Roma, putting him out of action during one of the best spells of his career.

"I wanted to express my personal gratitude and that of my family for the extraordinary affection which has been shown towards me in the last few days," Cassano wrote in the letter published on the club's website.

"The difficulties and sadness have been mitigated by so many demonstrations of affection from all over the world," added Cassano, who received messages of support from former club Real Madrid and arch-rivals Inter Milan.

"I will observe a rest period at home and I will be glued to the television to follow the fortunes of my Milan and the national team."

"A big hug to everyone and thank you."