Excuses. This team should be top 5 in rebounding in all categories (maybe not offensive rebounding).

They have the bigs to rebound and all of their other positions should be above average rebounders (RJ, Manu, TP are all good rebounders for their positions).
They're reasons more than they are excuses.

I agree, though, they should be a top five rebounding team. But what to do you expect when Duncan and McDyess are having their minutes managed and Bonner is regularly out there for 12-15 minute stints? It's bound to happen.

Blair needs to pick it up, though, no excuse for him. If he's not going to rebound better, then he has no business playing, because he kills this team defensively and is an afterthought offensively.