Italy striker Antonio Cassano will have heart surgery and likely be able to play again in a few months.
AC Milan says Cassano has been hospitalized since Saturday, when he was taken for tests after suffering what the club described as a brain problem on the team plane.
Cassano was reportedly joking with teammates on the plane, before suddenly developing problems with his vision, speech and movement.
Milan said in a statement that Cassano will undergo the heart procedure sometime in the next few days, and that his recovery time will be better determined after the surgery.
The club says Cassano has a cardiac anomaly which caused a brain problem due to impaired blood flow.