If you haven't checked out Start 'Em and Sit 'Em for this week, you should. You always should. Jamey Eisenberg offers the most helpful and complete start/sit advice there, and he's not afraid to go out on a limb.
For Week 15, he's advising Jets running back Chris Johnson at Tennessee. And certainly, there's some logic to it. I don't know that I buy the whole "revenge" angle because I think the game plan and supporting cast has just as much, if not more, to do with Johnson's performance than Johnson himself, but the game plan and supporting cast may work in his favor this week. He has seen an increase in carries lately, actually getting one more than backfield mate Chris Ivory the last two weeks, and the Titans are dreadful against the run, ranking dead last in the NFL. They're also allowing the second-most Fantasy points per game to running backs.
Still, Johnson is a platoon back for one of the league's worst offenses -- an offense that has averaged 14.0 points in its last five games. Johnson has scored only two touchdowns all season, and the last one came Week 4 against Detroit. He'll need big yardage to measure up in Fantasy, and there are no assurances of that.
It doesn't mean you can't start him, but only if you're in a pinch. I wouldn't get cute and play him over Alfred Morris, Rashad Jennings or Jeremy Hill, as Jamey's rankings suggest.