The Lions have placed defensive end Ziggy Ansah and tight end Michael Roberts on Injured Reserve with shoulder injuries.
Ansah reinjured his shoulder during last week's win in Arizona and had eight tackles and four sacks in the six games he played this season.
The move may signal the end of Ansah's career with Detroit as he was tagged as the team's franchise player in the offseason.
He was drafted into the NFL by Detroit in the first round in 2013 out of Brigham Young.
The Lions also announced yesterday that they have signed tight end Jerome Cunningham and offensive lineman Leo Koloamatangi from the practice squad to the active roster.