IMO, it depends on what you mean by "slump". Chances are, his stats are going to decrease, only because he did so well this year and now they have G. Jones coming back. He lead the league for RBs with more than 100 carries in ypc., so that's probably going to go down a tad. His TDs may very well go down as well, but that would be more due to Jax giving G. Jones some goal line work then it would him "slumping". So, from a FF perspective, he may very well decrease (if you want to call that slump), but I don't think it will be due to him performing poorly.
14 Teams, each keep 14 players
QB: P. Manning, Schaub
RB: MJD, Westy, C. Johnson, A. Bradshaw, J. Ringer
WR: TO, Driver, J. Gage, Crabtree, J. Morgan, K. Curtis, E. Bennett, M. Sims-Walker
TE: Witten, M. Lewis
K: Gostkowski, J. Brown
D/ST: Tenn, NE