Jackson (hip) was added to the injury report Friday and is listed as questionable for Sunday's matchup with Chicago, Tim Twentyman of the Lions' official site reports.
Adding him as a limited participant at the end of the week suggests Jackson was injured at some point Thursday or Friday. If he can't suit up ahead of the 1:00 p.m. ET kickoff this Sunday, the Lions will turn to Craig Reynolds as their No. 3 back behind Jamaal Williams and D'Andre Swift.