I've gotten the impression that AD is a rather private person and kind of self focussed. (I don't mean self centered or selfish). We hear about the OL working out in Whitworth's garage, meanwhile AD works out in Pittsburgh.
It was noted that Von Miller told AD he needed to become a vocal leader, then at half time told him that if he wanted to win a Super Bowl he had to play like he wanted it.
Just because he's been one of the best ever we fall into the trap of assuming he's a great leader as well. I just don't think that's AD. If he leads, it's by his example on the field and little more.
That said, I wouldn't be shocked if his no-show is an indication he's stepping away from either the team or the game.
