DALLAS — Michigan State head football coach Mark Dantonio announced Saturday the restructuring of his defensive staff for the 2015 season.

Secondary coach Harlon Barnett and linebackers/special teams coach Mike Tressel, who have both been on Dantonio’s staff since his arrival at MSU in 2007, have been promoted to co-defensive coordinators. Barnett also has been named assistant head coach.

Barnett and Tressel are filling the position left by former assistant head coach/defensive coordinator Pat Narduzzi, who was introduced as the new head coach at the University of Pittsburgh on Friday. Dantonio previously announced that Narduzzi will be coaching in his final game at MSU in the 2015 Cotton Bowl Classic against Baylor on Thursday, Jan. 1.

“It’s important to move the process forward, and I feel very comfortable in naming Harlon Barnett assistant head coach and co-defensive coordinator and Mike Tressel co-defensive coordinator,” Dantonio said. “Harlon and Mike have been on my staff together for 11 years, including the past eight years at Michigan State. They both have had a ton of input and shared a lot of ideas

with Pat Narduzzi over the years. The co-appointment ensures continuity in terms of player relationships, defensive concepts and terminology.

“Both Harlon and Mike have done a tremendous job in the individual day-to-day development of our players. Their relationships with our players are strong and true. I have a strong personal relationship with those two, and they will do an outstanding job in their new roles while continuing the legacy Michigan State has built on defense.

“I’m excited about maintaining our tradition of playing outstanding defense while continuing our quest for another Big Ten Championship.”

Ron Burton, who is in his second season at Michigan State, will remain coaching the defensive line. In addition, Dantonio will hire a new defensive assistant in the offseason.

“Change always creates opportunities for growth,” Dantonio said. “The additions of (defensive line coach) Ron Burton and (co-offensive coordinator and tight ends coach) Jim Bollman have enhanced our coaching staff.

“I’ll empower our coaches to have a say in the hiring process, as we complete the defensive staff. It will be a collective effort.”

Barnett and Tressel have been an integral part on the Spartan defensive staff that has assembled the No. 1 defense in the Big Ten since 2011. MSU has led the Big Ten and has been ranked in the Top 10 in the NCAA Football Bowl Subdivision the past three seasons (2011-13) in total defense and rushing defense, and is on pace for another Top 10 finish in both categories in 2014.

MSU enters the 2015 Cotton Bowl Classic ranked third in the Big Ten and seventh in the NCAA FBS in total defense (293.5 ypg.) and sixth in the FBS in rushing defense (97.5 ypg.).

MSU ranked No. 6 in total defense in 2011, No. 4 in 2012 and No. 2 in 2013, and No. 9 in rushing defense in 2011, No. 8 in 2012 and No. 2 in 2013. Michigan State and Florida are the only schools in the FBS to rank in the Top 10 in total defense every season since 2011 (including 2014). In addition, MSU is the only school in the FBS to rank in the Top 10 in total defense and rushing defense the past four seasons (including 2014).

Michigan State, which has ranked in the FBS Top 10 in scoring defense in 2011, 2012 and 2013, is currently 12th in the FBS in scoring defense (19.9 ppg.) through 12 games in 2014. MSU has allowed an average of 18.02 points per game over the last five seasons, which ranks as the fourth-best scoring defense average of any FBS team since 2010.