After graduating from Grand Valley State in 1985 with a degree in communications, he returned to Grand Valley as a graduate assistant where he worked with the offensive tackles and tight ends. He worked with current University of Notre Damehead coachBrian Kelly, whom assisted with the defensive backs in his first season as a graduate assistant in 1987. After two years, Denbrock moved on to Michigan State University where he helped with the quarterbacks and receivers on the 1988 Spartan squad that was selected for the Gator Bowl. The following season, he was moved to help with the offensive line as a graduate assistant on the 1989 team that played in the Aloha Bowl. His first full-time coaching assignment came in 1990–91 where he coached at Illinois State University, working with the offensive tackles and tight ends. In 1992, he returned to Grand Valley State, serving under Brian Kelly, who was then the head coach. From 1992–1995, Denbrock was offensive coordinator, coaching the quarterbacks and wide receivers. His offense was first in the MIFC in both total yards and scoring offense from 1992–94. He moved to defensive coordinator and linebackers coach from 1996–1998, where his defense ranked among the nation's top 30 in total defense, scoring defense and rushing defense each season. In 1996, his defense led the MIFC in scoring and total defense.
In 1999, he was part of the inaugural coaching staff for the AFL's Buffalo Destroyers. From 1999–2000, he held various coaching positions including associate head coach, defensive coordinator, as well as coaching the offensive and defensive lines. In his first season, his defense finished third in the league in both scoring and total defense, while in 2000, Denbrock helped the Destroyers land a playoff berth after a mid-season coaching change, where coach Dave Whinham was fired, being replaced by former NFL linebacker Ray Bentley.
Return to college coaching
Denbrock returned to the college ranks in 2001, working with the offensive tackles and tight ends at Stanford University. His line helped lead the way for a Stanford rushing attack which ranked 23rd in the nation, averaging more than 200 yards per game and scoring 27 touchdowns.
First stint at Notre Dame
In 2002, Denbrock was hired at the University of Notre Dame, to coach offensive tackles and tight ends. He was hired by then new coach Tyrone Willingham, whom Denbrock served under at Stanford. From 2002–2004, Denbrock's offensive tackles and tight ends were big factors as the Irish produced 1,000-yard rushers in 2002 and 2003. He also coached several players who later went onto NFL careers, including offensive linemen Ryan Harris, Jim Molinaro, Jordan Black and Brennan Curtin plus tight ends Anthony Fasano, Jerome Collins and John Carlson. Following Willingham's termination in 2004, new head coach Charlie Weis did not renew Denbrock's contract.
In 2010, Denbrock was hired by Brian Kelly, as he put together his inaugural coaching staff for the Irish. He spent the next two seasons coaching the tight ends, playing a major role in the development of future NFL tight ends Kyle Rudolph and Tyler Eifert. In 2011, Eifert was named an finalist for the Mackey Award, presented annually to college football's most outstanding tight end. Denbrock transitioned to coach the outside wide receivers and served as passing game coordinator in 2012 and 2013. Following the derpature of offensive coordinator Chuck Martin to Miami University, Denbrock was named interim offensive coordinator for the 2013 Pinstripe Bowl vs Rutgers. On January 30, 2014, Denbrock was officially promoted to offensive coordinator.