The Lions placed Barnes (knee) on injured reserve Tuesday.
Barnes will miss at least Detroit's next four games due to a knee injury sustained in Sunday's 20-13 win over the Cardinals. Coach Dan Campbell alluded to a significant recovery timetable for Barnes, so it's possible the starting linebacker could be out longer. Malcolm Rodriguez played a season-high 87 percent of defensive snaps Week 3 and figures to continue handling an expanded role versus the Seahawks on Sunday.