The Spurs weren't exactly setting the world ablaze when Duncan and Parker missed playing time. Plus, any bench is going to look like crap if you take away the two best players.
One can argue that Manu is the best player on the team but pointing at how the team plays without him isn't going to win the argument.
Without Vaughn - 7-1
Without Ginobili - 4-2
Without Barry - 3-2
Without Duncan - 2-2
Without Elson - 1-2
Without Parker - 1-3
Unless, of course, you want to argue Elson as the second best player on the team.
