Well, they did try to get a replacement for Diagne (or insurance), and I think they thought they had it with Thomas Bryant.
Joseph - they may have known he wouldn't be as impactful as a 5th year senior Mike G, but that is a far cry from saying he would not even be serviceable in any way for a single minute of meaningful game action!
And on top of that there is no way to know that in addition to that, he would also transfer. And that Obokoh would transfer. As it turns out, BJ Johnson and Kaleb would have gotten substantial run next year (if MR doesn't return). But it only highlights how hard it is to manage the roster and like I said the sanctions (that also change over time in unexpected ways) compound the problem. This is not a pro franchise that can be managed in line with a salary structure and union rules. It is almost totally unpredictable in all the important aspects. That's my only point.