If he doesn't make some improvement, then, sure, cut his minutes at some point. But if Rose doesn't play him now, there is not much chance that he will develop into a contributor this year (and there is some chance he will develop quite a bit with experience given how raw he is).

So I'd Rose to show more patience with Kafusi before he cuts his minutes back. (Well, and given the amount of fouls our bigs tend to get, we will need Kafusi to play a fair amount this year.)