Some food for thought- last year, you could replace Chris Johnson's name with MJD in this conversation. MJD started very slow, everyone began saying he was done, that the team wasn't good enough for him to produce, that his knee injuries were going to wreck his season, that he had lost a step, that he seemed disinterested, etc... All MJD did after his slow start was perform as a top 3 RB (heck, even the top RB for quite a stretch) for the last 2/3 of the season until he missed week 16 with an injury.The moral of this story is that, in almost all situations, talent will win out (especially elite talent of the Chris Johnson variety). If you have a chance to acquire Johnson for less than what it should cost to acquire him (if he had started out the season playing at his normal level), then you absolutely should jump at the chance. Even if it doesn't pan out, the idea of acquiring elite talents at a discount is good process regardless of the individual outcome.I recently traded Jahvid Best and Rob Gronkowski for Chris Johnson and Bernard Scott in one of my keeper leagues to give some context for his value for those looking to get him (although it is not apples to apples as there are keeper costs, contract lengths, etc... that alter true values of players in that league).