New England’s system not only challenges you physically, it challenges you mentally, because they have so many concepts and so many things going on within that offense,’’ said Holt, now an NFL Network analyst. “Tom runs that offense to a T and he has the flexibility to change things at the line of scrimmage at any given time.

“You have to know a number of things all the time. That’s just the plays. I’m not even talking about the snap counts that he has the ability to change if he wants to. There’s a lot within that offense that you have to know and be able to do quickly. And not only know it, but now you have to go out and execute it – and for a lot of young guys and even veterans, that can be intimidating.’’