He wants to go back to playing offense. While I thought he was a natural at rover, and he had a great nose for the position, I get he wants back on the other side of the ball.
The bigger problem is Pruitt is now dealing with a very thin defensive backfield, one that he's taken great pains to point out that he's not happy with. Also, one that he's gone to great lengths to make it uncomfortable enough for some of those guys to transfer. He has to show the recruiting prowess he is known for and now.