Rutgers football practice, 11-22-16

Rutgers assistant coach Bill Busch will remain in charge of the safeties in his new role as co-defensive coordinator.

(John Munson | NJ Advance Media)

Bill Busch is climbing the ladder at Rutgers.

After one season as defensive backs/safeties coach, Busch, who followed Rutgers coach Chris Ash from Ohio State, recently was promoted to co-defensive coordinator, as highlighted in his official coaching staff biography.

Busch has been a defensive coordinator twice before in his career: At Northern Arizona in 1996 and at Utah State in 2009-10.

Defensive coordinator Jay Niemann, who was Ash's position coach as a player at Drake in the 1990s, is expected to remain the play-caller on that side of the ball. Niemann came to Rutgers after four seasons as the defensive coordinator at Northern Illinois.

Since arriving in Piscataway, Busch has built a strong reputation in the fertile North Jersey recruiting ground and sparked a significant turnaround in the pass defense.

The three worst single seasons in school history in terms of passing yards allowed preceded the hiring of Ash, a former defensive backs coach. He tapped Busch, who was a quality control assistant at Ohio State, to lead the position.

Rutgers ranked No. 18 nationally in passing yards allowed per game (186.5) last season, though the stat might be somewhat misleading because opponents rushed for 264.2 yards per game. Either way, it was a big improvement from ranking in the bottom 10 nationally twice from 2013-15.

Ash is no stranger to the concept of co-coordinators with one play-caller. He and Luke Fickell shared the title at Ohio State and now both are head coaches following Fickell's hire at Cincinnati.

Ash and his longtime close friend Charlie Partridge were co-defensive coordinators at Wisconsin in 2011-12. Partridge is now the defensive line coach at Pittsburgh after he was fired from a stint as Florida Atlantic's head coach.

Despite Rutgers finishing with a 2-10 record at the start of a rebuilding project, several of Ash's assistants were sought-after for other positions. Rutgers retained offensive line coach A.J. Blazek and Busch but replaced Drew Mehringer, Zak Kuhr and Aaaron Henry.

Busch remains in charge of the safeties, while newly hired assistant Henry Baker coaches the cornerbacks.

Ryan Dunleavy may be reached at rdunleavy@njadvancemedia.com. Follow him on Twitter @rydunleavy. Find NJ.com Rutgers Football on Facebook.