I have said from the beginning that I think he is injured. (I refuse to speculate on the severity of the injury.) But I think there are multiple issues at play at this point. I just know that none of the narratives I read dissing Kawhi seems to take into account that the guy has been a gym rat who is driven to play basketball, and none of the narratives I read fluffing the guy can account for his going completely AWOL. Kawhi isn't improving his earning power through all this and PATFO isn't increasing his marketability. The uncle narrative makes some sense. Having dealt with depression my whole life, I suspect he has some mental/emotional issue such as depression or bi-polarism, which makes the uncle narrative seem more plausible to me.
SAGirl's idea that he is dealing with a degenerative, career-threatening condition makes some sense to me. I do not have any clue why he wouldn't address his condition in clear, regular statements as any other athlete has in the past and would have in Kawhi's current situation. The thing that is clear is that he does not want to be the team leader and the face of this franchise - or, more than likely, any other. He may not even want to be an Alpha on the court. He has always wanted to play, and he has always wanted to win. He is doing neither now, and that can't make him happy.