The Lions placed RB Kevin Smith on injured reserve Saturday, ending his season.
Smith injured his thumb in Detroit's 14-12 loss to Buffalo last week, and the team felt it needed his roster spot, using the opening to promote LB Caleb Campbell from the practice squad to the 53-man roster.
Smith had 34 carries for 133 yards (3.9 avg.) and 11 receptions for 123 yards. He missed the last three games of 2009 with a knee injury.
Maurice Morris will assume the No. 2 RB spot behind starter Jahvid Best.