Allen (hamstring) has been ruled out for the remainder of the Broncos' game against the Panthers.
Allen was making his first appearance with Denver after signing with the team's active roster Tuesday. Over four games with Cleveland earlier this season, the 27-year-old logged two tackles while playing all 57 of his snaps on special teams. With Jonas Griffith (ankle) on IR, Allen's absence will leave Alex Singleton, Josey Jewell and Justin Strnad as the Broncos' only available inside linebackers Week 12.