 As head coach from 2005 to 2009, DeBoer had a record of 67–3 and won three NAIA national championships in 2006, 2008, and 2009 and a runner-up appearance in 2007.Two of DeBoer's losses at Sioux Falls came at the hands of Mike Van Diest's national title-winning Carroll Fighting Saints squads in 2005 and 2007.DeBoer was the offensive coordinator at Southern Illinois from 2010 to 2013 under Dale Lennon.