Marinelli joined the
Chicago Bears in January 2009 as assistant head coach and defensive line coach,
[2] reuniting him with
Lovie Smith, whom he worked with under
Tony Dungy in
Tampa Bay from 1996–2000.
[2] Marinelli also interviewed with the
Houston Texans and
Seattle Seahawks before joining the Bears. Marinelli was promoted from defensive line coach to defensive coordinator in February 2010.
[3] In the 2010 to 2012 seasons, Marinelli's defenses ranked ninth, seventeenth, and fifth, respectively. Also in 2012, the Bears led the NFL in interceptions with 24,
[4] along with in takeaways with 44, sixth in third-down efficiency (35.5 percent) and eighth in sacks with 41,
[5] while ranking third with the fewest points allowed (477).
[6] Marinelli left the Bears in January 2013.
[7]