The Titans running back would have been much further up the list in years past. His numbers last year were hardly bad -- 276 carries for 1,243 yards and six touchdowns. But he was often hesitant and had far too many carries for a loss or no gain.
He may be primed to move way up the list, given that the Titans revamped the inside of the offensive line and have rededicated to the run game.
From ESPN Stats & Info:
Johnson had three rushing touchdowns of at least 80 yards last season. He has six for his career, twice as many as any other player in NFL history. However, since coming into the league in 2008, Johnson has a league-high 81 carries on which he lost 3 or more yards.
From Football Outsiders:
Johnson is certainly blessed with natural speed, but he has a boom-or-bust style that is absurdly dependent on first-level blocking. If there's no clear hole, he dances around instead of taking available yardage. As a result, he has been very inefficient for the past three seasons.