Well 43,
that's one way of looking at it, here is how I see it. This is week one of Preseason coming up, they are not going to play Donald much if at all, Brockers too for that matter.
I think this kid is being brought in to give some more depth to the position for the preseason games and that's it. once the cutdown from 90 happens then you may want to start questioning why. until then, just go with the flow and realize its preseason and they already know what Donald can do, no sense in risking him, but the other guys also need breathers and limited time.

TGIF (Thank God Its Football)