No matter how prepared or healthy or rusty EJ is, it would be smart to pound the ball all day long: Spiller right, Spiller left, Jackson right, Jackson left, we may even give Choice a carry or two, and who's our fullback now? give him a few as well, etc.
And let's not forget, for all the excitement about our new highly aggressive defense (which I'm all in favor of), they were still getting gashed in the preseason running game (which was a huge issue last year--NEWS FLASH: our biggest problems from last year was not the QB or the offense). The longer we can keep our defense off the field, the better for everyone.