If Grav is out, while that would be bad in itself, cos I like the start he's made, it does mean that Harvey can come in and give us some width down the right. I think that has been something we are missing. Mo likes to come inside, as we know, even more so as he gets older. And with Trent tucking in, it is really only when Harvey comes on that we actually have somebody going out and using the space out wide (and there is usually plenty of it, with Mo dragging the LB inside).
Against Luton there was acres of space on the right and we never used it til Harvey came on. So, while Grav himself would be a miss, Harvey could give us some of the width we are foregoing with the Trent false RB experiment.