Summers was elevated from the Lions' practice squad to the active roster Saturday.
Summers has primarily contributed to the Lions as a special teamer this season, playing 12 snaps in the Week 5 contest against the Bengals and 14 in the Week 6 contest against the Chiefs. The linebacker has likely been elevated to fill a similar role in Sunday's divisional matchup with the Vikings, but he will also be the primary backup to Jack Campbell at middle linebacker due to the absence of Zach Cunningham (hamstring).