Williams suffered a shoulder injury during Thursday's game in Washington, Joe Hoyt of The Dallas Morning News reports.
After his four-yard touchdown run early in the second quarter, Williams didn't receive another touch before the Cowboys deemed him questionable to return. If he's unable to get back into the contest, he'll end Week 17 action with 13 carries for 54 yards and the aforementioned score and no catches (on two targets). Malik Davis should garner most of the RBs reps for as long as Williams is sidelined, but FB Hunter Luepke also is on hand for snaps.