As much as I am bitter as a Celtics fan towards Kyrie, I am inclined to give him the benefit of the doubt that he is, in fact, dealing with a serious personal issue. If that's the case, it's the prerogative of the player and the team to keep the details private. I think the concern is that he's outraged about recent events (understandable) and just doesn't feel like playing, in which case he and his team should come out and say so. But again, it's hard to know and I personally am trying not to speculate too much.