Hillis has had attitude issues, and he's been a one year wonder. I very much doubt he's on the radar because he doesn't really have any special talents, either. He's a bulldozer, but we don't need one of those at this point.
Also, RBs in a zone system tend to be somewhat expendable unless they're like Marshawn. Thus, you try to draft them and take fliers on the ones you think might work when it comes time for that rather than trading for them.
Welcome to the board.
Super Bowl Champions XVLIII