Washington (undisclosed) wasn't present for the Lions' walkthrough Thursday, Michael Rothstein of ESPN.com reports.
The details behind Washington's absence aren't known, but it's likely he's dealing with an unspecified injury. If that's the case, Washington could be withheld from the Lions' second preseason game Friday against the Giants, denying the running back an opportunity to impress the coaching staff while he remains in a tight battle for a roster berth. Washington seems to be competing with LeGarrette Blount and Zach Zenner for one spot as a bigger, short-yardage back.