Let me preface this by saying that I completely understand why Nate is reluctant to go to the bench. The bench has been, for lack of a better word, terrible. Our bench is regularly being outscored by 20+, so it is no mystery why Nate gives them so little court time. But Nate's refusal to use the bench is kiling our starters, particularly, and most importantly, Aldridge. It is a very good thing Roy took over the game in the last quarter, because I'm certain Aldridge did not have enough left in the tank to do so. Aldridge is our main option on offense, and he is generally guarding Nowitzki of defense. This means he is playing the most important, and most sapping, role on BOTH ends of the floor. Now when you add to this that he basically NEVER gets any real rest on the bench, it is no shock that he looked like he was going to pass out at the end of Game 4.
Nate, play the bench. Not because they deserve it (they haven't showed anything). Not because the bench are likely to have great games (they might, but probably not). But because what you are doing with the starters, especially Aldridge, is the equivalent of riding a horse to death.