Karras was a
graduate assistant at the
University of Minnesota in 1991 and at
Northern Illinois University in 1992. He then worked as a defensive assistant at
Lake Forest College from 1993 to 1994 and as a defensive line coach at the
University of St. Francis in 1995. In 1996, Karras became the head football coach for
Andrean High School in
Merrillville, Indiana, and took his team to the state championship, the first appearance in school history, where they lost to
Bishop Chatard High School of
Indianapolis. In 1999, Karras moved on to
Saint Xavier University in
Chicago as
offensive coordinator. After four years at Saint Xavier, Karras moved to
Terre Haute, Indiana to become head football coach at
Rose-Hulman Institute of Technology. In 2006, Karras took the job of coaching the inaugural football team at
Marian University. In the football program's sixth year of play in 2012, Karras led the Knights to the
2012 NAIA Football National Championship, where they won 30–27 in overtime. After the 2012 football season, Karras left Marian to become the second head football coach in
Walsh University's school history, replacing
Jim Dennison. Walsh, located in
North Canton, Ohio, formally introduced Karras as the Cavaliers' new head coach on December 21, 2012. At the end of the 2016 season, in which the Cavaliers compiled a 1–10 record, the worst in program history, Walsh University announced that Karras would no longer be coaching the team. On December 22, 2022, Karras returned to Marian as head football coach for the 2023 season. ==Head coaching record==