Milan, Italy – AC Milan has confirmed that striker Antonio 2 win over Roma on Saturday.
The 29-year-old was taken to the hospital after suddenly developing problems with his vision, speech and movement on the plane home from Rome.
A series of tests failed to diagnose the problem but it has now been discovered that Cassano suffered ischemic-based cerebral damage and will have an operation this week.
A statement from AC Milan read: "The cause was identified as the presence of a patent foramen ovale septal heart, detectable only with sophisticated specialized tests. The timing of therapy established has allowed a rapid recovery and an improvement of clinical conditions that are good.
"In the coming days the player will undergo a small surgical intervention cardiology (closure of the foramen ovale), the recovery time for return to playing will be better defined after the surgery, but probably will be a few months."
Cassano has appeared in nine Serie A matches for Milan this season, scoring two goals, and he announced last month that he would retire from the game in 2014.