This caught my eyes: "Shanahan also said that he’s feeling good, and that his head “feels so much better.” He added that he’s still dealing with “headaches and fatigue.”"

As someone who suffered from the same symptoms after a concussion, what Kyle said is not good news. The fatigue he is talking about is the mental fatigue from post concussion syndrome. He will be operating at a reduced level. If he pushes himself to function the same way he did before, he is going to make symptoms worse. He does have a full compliment of staff and coaches under him. He will have to delegate far more this coming season as an adjustment.