Jeff Green will miss the entire 2011-12 season after a heart ailment known as an aortic aneurysm was discovered on a routine physical.
The condition will require surgery but Celtics doctors say Green will be able to resume his career next season.
The surgical procedure will be performed on January 9.
ESPNBoston is reporting that Green's one-year, $9 million contract is expected to be voided as a result of this medical problem. Boston would retain his rights.