Need some RB help for the playoffs?

Right now I am starting Ryan Grant, Larry Johnson, and Sammy Morris. I have Maurice Morris against STL (and can also pick up Julius Jones since no one knows who will start) and I also have Tatum Bell who looks like will be the starter in Denver. Should I leave it the way I have it? Sammy Morris concerns me with split carries, and LJ concerns me because they will probably fall behind and have to throw a lot.