The rumor is that Jeff Green’s undisclosed health issue involves a heart condition, but details have yet to be made public. From “A source close to Boston Celtics forward Jeff Green says the 6-foot-8 forward is expected to miss some games early on this season due to an undisclosed health condition that became apparent during his most recent physical. Green, accompanied by president of basketball operations Danny Ainge, were at an undisclosed location on Friday seeking a second opinion. Head coach Doc Rivers had expressed optimism earlier in the day that the results from that second opinion would be back in time for him to discuss Green’s status following Friday night’s intra-squad scrimmage at the TD Garden.”