If we could play 4 on 5 for spurts, still win and it meant Pierce and Ray Allen got the proper rest, I'd be all for it. So the fact that Walker may have looked invisible is irrelevant if it means Pierce got some rest. Perhps if Pierce weren't rested last night he might have had a little less lift which may have resulted in rimming the game winning shot and us losing the game becasue he was spent?
I also agree with some who say leave them out there a bit longer if they're not losing the lead or if they are increasing. I'll take it a step further, I'd leave them out there ( Marbury, Pruitt, Walker, Moore, Powe or baby ) the rest of the game if they were winning it. Gets them great, great experience. And the season is a real grind for the starters. They won't mind the rest and they certainly won't lose their ability by getting more rest when they can.
In the end, you might jsut have a much stronger "team" come season's end with more depth. And "team" wins...
Now, if the subs are tanking, yank em asap. But if they're rolling, let them run...