The injury to Moreno sounds potentially disastrous, as described by the MSM.  The injury to McGahee, our best running back, maybe less so, but might still cause him to lose time or be less effective.

If both of them are unavailable for a game or two, who might be available from the Practice Squad or as a free agent, or is there another player already on the team who could be pressed into service (Rosario, Green, etc.)?

After all, if you're going to live and die by the running game, you need to have runners.  Or maybe they could let the QB throw a couple more passes, preferably on an earlier down than 3rd down.