Rod Marinelli Rodney Marinelli ( born July 13 , 1949 ) is an American football coach who is currently the defensive coordinator for the Dallas Cowboys . He was fired from his position as head coach one day after coaching the Lions to the worst single - season record in NFL history , 0 – 16 in 2008 . Early coaching career . Marinelli ' s coaching career began in 1973 as an assistant at Rosemead High School in suburban Los Angeles from 1973 to 1975 . He earned his first collegiate job in 1976 , serving as an assistant to Pape Swalpek at Utah State University until 1982 . He then moved on to the University of California for nine seasons , serving as the defensive line coach and later the assistant head coach . He was then on staff with Arizona State University for three seasons , again holding a dual role as defensive line and assistant head coach , between 1992 and 1994 . Marinelli spent his final year in college football at University of Southern California in 1995 . Professional coaching . Marinelli went to the Tampa Bay Buccaneers in 1996 and was the defensive line coach for 6 seasons under head coach Tony Dungy . The latter four seasons he also served as assistant head coach . He was known for his structured approach and his commitment for trying to get the most out of his players . There he worked to develop lineman such as Warren Sapp and Simeon Rice into Pro Bowl caliber players . During Marinelli ' s tenure in Tampa Bay , the Buccaneers earned more sacks than any other franchise . Detroit Lions . On January 18 , 2006 , Marinelli was named the head coach of the Detroit Lions , replacing Dick Jauron . Marinelli was the fourth coach hired by Lions CEO Matt Millen , preceded by Marty Mornhinweg , Steve Mariucci and Dick Jauron . The Marinelli era began poorly , as the Lions lost the first five games of the 2006 season before beating the Buffalo Bills 20 – 17 . The Lions lost seven games in a row between weeks 10 and 16 before ending the year on a high note by beating the Dallas Cowboys 39 – 31 . The 2007 season started off well for the Lions as they started 6 - 2 . However , the Lions lost seven out of their last eight games , and finished the 2007 season 3rd in the NFC North with a 7 – 9 record . Despite a perfect 4 – 0 preseason , Marinelli coached the 2008 Lions to an 0 – 16 season , the first team in NFL history to lose every game of a season since a 16 - game regular season was instituted in 1978 ( The last team to lose all of their games was the 1976 Tampa Bay Buccaneers , who went 0 - 14 ; the last team to not win a game was the 1982 Baltimore Colts , who were 0 - 8 - 1 in a strike - shortened campaign . ) On December 26 , 2008 , Marinelli was fired , in addition to the majority of his coaching staff . His record during the 3 seasons with the Lions was 10 – 38 , one of the worst in NFL history for a head coach with at least three years ' experience . Among coaches with at least 10 career wins , only Bert Bell has a worse record ( 10 - 46 - 2 ) ; Steve Spagnuolo posted the same 10 - 38 mark as Marinelli . Chicago Bears . Marinelli joined the Chicago Bears in January 2009 as assistant head coach and defensive line coach , reuniting him with Lovie Smith , whom he worked with under Tony Dungy in Tampa Bay from 1996 – 2000 . 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 . From 2010 to 2012 , Marinelli ' s defenses ranked ninth , seventeenth , and fifth , respectively . Also in 2012 , the Bears led the NFL in interceptions with 24 , along with in takeaways with 44 , sixth in third - down efficiency ( 35 . 5 percent ) and eighth in sacks with 41 , while ranking third with the fewest points allowed ( 477 ) . Marinelli left the Bears in January 2013 . Dallas Cowboys . On January 18 , 2013 , Marinelli joined the Dallas Cowboys as defensive line coach . Marinelli was promoted to defensive coordinator after the demotion of Monte Kiffin on January 28 , 2014 . Personal . Marinelli and his wife , Barbara , have two daughters , Chris and Gina . Chris is married to Joe Barry , the former Lions defensive coordinator . Marinelli is a veteran of the Vietnam War .