You have a similar problem as me. I would rule out Mendy, He's going up against one of the best run defenses in the packers.
so you have Jennings , foster, and Ganther left.
I would definately play Jennings, he's been named the starter against a sad run Def. at KC. Even if he splits some with Cribbs I think he will do great.
Foster is a risk, he could do great, or be a bust, and his coach could bench him if he has a fumble. hi risk reward with Foster.
Ganther is not going to split many runs with Cartwright so he will be the #1 runner, and Giants have some injurys on the def line and their safety is horrible. I would pick Jennings and Ganther.....or if your feeling lucky, Jennings and Foster. just my thoughts. goodluck