Josh Looney of KCChiefs.com reports that Chiefs RB Kolby Smith has been formally ruled out for Sunday's game against the Broncos.  This is about what we expected when he wasn't on the practice field this afternoon.

Meanwhile, as I just noted a few minutes ago, Kent Babb of the Kansas City Star believes this could be the season ending variety of injury.

"Chiefs RB Kolby Smith's injury could be season-ending," Babb reports.  "The team will know more after today, but he again could be placed on IR."

If that's the case, it'll be the second time Smith has been placed on IR in his short career.

Looney also reports the Chiefs put RB Dantrell Savage as doubtful on the injury report.  This means he has about a 25% chance of playing, or highly unlikely.

So, it's nearly guaranteed that the Chiefs running backs on Sunday will go like this:

1. Jamaal Charles

2. Tim Castille/Mike Cox (FBs)

It's also possible the Chiefs make a decision on Smith after today and, if it is IR, rookie RB Javarris Williams is sitting on the practice squad.

The Chiefs also worked out former Bengals RB Chris Perry a couple weeks ago so that's a possibility.