It's a very good question.
Though it is clear that his intent is to run less, there is a snap or three per game when he is on his way to, but another lane collapses (OL sustain fail) and he gets tackles before getting through.
Otherwise, it is either
(a) an injury tweak that he is being cautious over
(b) Andy/Alex are afraid of an injury, so is prompted to avoid running as much as possible.. at least for reg. season games
