He was not ready. It is that simple. Early on he looked lost. He often played out of control, and made massive mistakes on defense, often finding himself out of position. He also was not ready, with regards to his fitness. He was not that far removed from his mission and he needed to get back into shape.
I have some inside info on this, and I am not going to post some of what I know, but I do know that he still struggles at times with schemes and plays and where he's supposed to be. But I know for a fact that coaches are working with him constantly going over the nuances of the game plan. He is doing much better with this but still has lots to learn.
You can say what you want but you are completely wrong on multiple levels.