Mark DeLeone enters his 10th season as an NFL coach and first as the Detroit Lions' inside linebackers coach in 2021.
DeLeone spent the past two seasons (2019-20) as the inside linebackers coach for the Chicago Bears. In his two seasons in Chicago, the Bears allowed the sixth-fewest points (668) and tied for the fourth-fewest touchdowns allowed (74). He helped develop LB Roquan Smith, the eighth overall pick of the 2018 NFL Draft, to Second-Team AP All-Pro honors in 2020. Smith produced 100-tackle seasons in both years under DeLeone's tutelage.