Hopefully, him barely playing is just to give him a kick in the ass and show him that he's not going to just be handed 15-20 minutes every game on the count of him being one of only two centers on the team and that he'll have to play tougher and play through the occasional hang nail to get those minutes.
If not and Pop is seriously contemplating this (or has made a final decision altogether), then he needs to be fired. Seriously. Not only would that be insane, but it would also be hypocritical. Four straight training camps he's pretended as if defense is the focus and going on four straight years, we've seen nothing but evidence to the contrary.