If Foster is out yes, but I have yet to see anything definite that he will be. Keep an eye on the inactives.
Ian Rapoport just reported that Foster is a "long shot" to play this week. Keep an eye on this. I would start Blue if/when they announce Foster as inactive.
.5 PPR I would. I might even consider playing Jennings over Blue as well since we don't know how much of a workhorse he'll be.
