The Broncos placed Johnson (hamstring) on injured reserve Saturday, Parker Gabriel of The Denver Post reports.
Aric DiLalla of the Broncos' official site reported Friday that Johnson was considered a game-time call for Sunday's contest against the Chiefs after sustaining an injury during Thursday's practice, but his inability to practice Friday indicated that the injury was more severe than previously thought. Johnson will now have to sit out for the next four games and will be eligible to return against the Texans on Dec. 3.