He left last week's game against the Miami Dolphins with cramping but said tests taken after the game showed no pull or defect in his groin muscle. He was, however, limited in practice due to the short week and as a result the Cowboys will add Phillip Tanner to the roster today to have a second fully healthy runner available for the Broncos.
If Williams can't play, he will have to rest his case on what he did in three preseason games. He leads the Cowboys with 112 rushing yards on 25 carries and a touchdown. He also leads the Cowboys with nine catches, good for 66 yards.
But is it enough?
Not even the Cowboys know for sure.
They have so many questions on the roster that they might not be able to carry four tailbacks. Joseph Randle will not play against the Broncos because of an oblique strain, but he appears to have the inside track behind DeMarco Murray and Lance Dunbar. He's also been a better special teams player.
The third tailback has to contribute on special teams and Williams acknowledged that has been new for him. As a former second-round pick of the Arizona Cardinals, he wasn't asked to chase down punts and kicks. He's worked at it, according to Jason Garrett.
What Williams has done is put himself in the conversation not only for the Cowboys' roster, but for another team. If he is waived, he should get a second chance. Perhaps the Cowboys could find a willing trade partner looking for a back.
Or perhaps the Cowboys keep him, knowing that Murray and Dunbar have not played a full schedule in their short careers.
"The one thing I do know is it's a numbers' game and it's a business," Williams said. "At the end of the day, you can be as good as you want to be but they might not need you at the end of the day. So you go out there and play as hard as you can and you don't worry about the rest."