Since regaining the primary back duties after the season-ending injury to rookie DeMarco Murray, Jones has 38 carries for 214 yards, but his hamstring tightened up during last Saturday night's win over the Tampa Bay Buccaneers. Jones' hamstring could keep him out of or reduce his role against the Eagles' 17th-ranked run defense.
To account for a possible increased workload for veteran Sammy Morris, who was signed last week, the Cowboys have signed running back Chauncey Washington off the practice squad. Washington has just four carries for nine yards in his career, but if active, he would fulfill many of the special teams duties that Morris has filled as the No. 2 back behind Jones.
For more on the Cowboys running back situation, check out Blogging The Boys.