Sensabaugh, who injured the thumb in last week's 17-10 loss to Denver, had surgery on Monday, and may miss up to four weeks.
Williams was also injured in Denver, the result of a shot to the ribs delivered by the Bronco's D.J. Williams.
Felix Jones will sit out for the second week in a row with a sprained right knee.
Pat Watkins will step in for Sensabaugh, and Miles Austin will get his first start of the year if Williams is unavailable. Like last week in Denver, the rushing attack will consist of Tashard Choice, and Marion Barber, who was listed in the official report as "probable."
*Jerry Jones said today on 105.3 The Fan that, even in the vent of a loss to the 0-4 Kansas City Chiefs, Wade Phillips' job was safe.
*Jay Ratliff was fined $7,500 by the league today, the result of a roughing the passer penalty on Denver's Kyle Orton.