Debeljak was named head football coach at Case Western Reserve on March 24, 2004 after serving the previous three seasons as offensive coordinator for the program. Debeljak had a rough start in his early years at Case Western but found significant success in the seasons following 2006.
2004 In his first year as head coach, Debeljak led the Spartans to a 5–5 overall record and 2–1 mark in
University Athletic Association (UAA) play. The Spartans played their home games at
Brush High School's Korb Field in nearby
Lyndhurst, Ohio while the
DiSanto Field was under construction, which would be completed for the 2005 season.
2007 After a disappointing season the previous year, Debeljak and his team found success in 2007. The Spartans went undefeated in conference play and 11–1 overall with an appearance in the second Round of the
NCAA Division III playoffs. The 2007 Case Western season ended with a 38–23 loss to the
Wabash Little Giants. Debeljak was selected as one of five finalists for the NCAA Division III
Liberty Mutual Coach of the Year Award in 2007.
2008 The Spartans carried their success into the 2008 campaign with an undefeated regular season and a second consecutive UAA Title. Debeljak's achievements earned him the "Lee Tressel Ohio College Coach of the Year Award" in 2008. He was again a finalist for the NCAA Division III Liberty Mutual Coach of the Year Award.
2009 The 2009 Case Western team saw continued success with another undefeated regular season and their third straight conference championship. The Spartants repeated their record of 10–1 from the previous season and lost in the first round of the NCAA Division III playoffs. Case Western Reserve ended their regular season with a seventh-place ranking in the final
American Football Coaches Association (AFCA) regular season poll—their highest regular season finish under Debeljak. Debeljak was again selected as one of five finalists for the Liberty Mutual Coach of the Year Award.
2010 On October 30 2010, the Case Western Spartans lost to the
Chicago Maroons at the
University of Chicago's
Stagg Field. This loss ended the Spartans' 38 game regular season winning streak going back to the final game of the 2006 campaign. The 2010 season ended on November 11 with a fourth straight win over rival
Carnegie Mellon.
2011 The 2011 Case Western team ended with another win over Carnegie Mellon and a 9–1 overall record. The Spartans went undefeated in conference play and claimed their fourth UAA title in five years. On December 13, 2011, after 27 years with the
University Athletic Association, the Case Western Reserve Spartans announced they would join the
Presidents' Athletic Conference (PAC) prior to the start of the 2014 season. Case Western Reserve was a founding member of the PAC in 1955 but left for the
North Coast Athletic Conference in 1984. They joined the UAA two years later. Rival Carnegie Mellon announced they would also join the PAC with the Spartans.
2014 The Spartans went 3–7 overall with a last place finish in their inaugural season as a member of the PAC.
2015 In 2015, the Spartans improved upon their previous season by going 7–3 overall with a third-place finish in the Presidents' Athletic Conference. This was Debeljak's tenth top-three conference finish in his 12 seasons as a head coach.
2016 The Spartans finished 9–1 finishing 2nd in the PAC and sharing the UAA champion title at 2–1.
2017 The Spartans finished the regular season an undefeated 10–0, sharing the PAC conference title with 10–0
Washington & Jefferson. In its final season of play, the Spartans also won the UAA title at 2–0. Coach Debeljak recorded his 100th career win against
Westminster during the ninth game of the season on November 4, 2017. In the first round of the
NCAA Division III playoffs, Debeljak's Spartans shut out the
Illinois Wesleyan Titans 28–0 in a game that saw heavy snow. In the second round, the Spartans were soundly defeated by the
Mount Union Purple Raiders 45–16.
2018 The Spartans ended the year 8–2 finishing 2nd in the PAC and 2nd in the UAA.
2019 ==Head coaching record==