Promoted to assistant head coach for 2012 season.
Diaco won the 2012 Broyles Award as the nation's top assistant coach, the first Irish assistant coach to ever capture the award.
Diaco's defense in '12 ranked among the top 10 in the Football Bowl Subdivision in 12 different categories.
Notre Dame ranked second in the FBS in scoring defense in '12 - allowing just 12.77 points per game. The Irish were one of just three scoring FBS top-10 defenses to exclusively face FBS competition. Notre Dame only allowed 16 touchdowns (only 15 offensive touchdowns) - four fewer than any other FBS school.
Notre Dame allowed a total of 166 points over its 13 games in '12. The Irish have never surrendered fewer points over a 13-game season in school history.
Notre Dame allowed 12 offensive touchdowns over its last 11 games of '12.
The Irish held six opponents without an offensive touchdown and nine foes to one or fewer offensive touchdowns.
Notre Dame limited 10 opponents to 14 points or less. The Irish have not held more foes to 14 points or less in a single season since 1921.
Notre Dame limited five different opponents to single-digit scoring efforts, including No. 10 Michigan State (3), No. 18 Michigan (6), Miami (3), Boston College (6) and Wake Forest (0). The five such games in '12 surpassed the combined total of the previous four seasons (2008-11).
Semifinalist for the 2011 Broyles Award, presented annually to college football's top assistant coach.
The 2011 defense ranked in the top 50 in scoring defense (24th, 20.7), total defense (30th, 344.7), rushing defense (47th, 138.9) and passing defense (38th, 205.8). It was only the second time since 2003 and fourth time in the last 15 seasons a Notre Dame defense ranked in the top 50 in all four categories.
Led a defense that held 12 of 13 opponents below their season scoring average and 11 of 13 teams below their season rushing average.
For the first time in 10 years, Notre Dame's defense allowed fewer than 21 points per game in consecutive seasons. The Irish are one of six teams to allow less than 21 points per game in each of the last three years.
Diaco's defense surrendered 14 points or less in five games in 2011, the most since 2002.
The rush defense was stingy near the goal line in 2011 as only eight rushing TDs were scored against Notre Dame. Only four schools permitted fewer rushing TDs. Of those eight rushing TDs, only three were scored by running backs.
The Irish defense was nothing short of sensational in the third quarter as Pittsburgh and Florida State were the only teams to score against Notre Dame in the first period following halftime.
Coached the linebackers and helped the growth of Manti Te'o who led the team with 128 tackles, 13.5 tackles for loss and five sacks. Te'o was a second-team All-American and a finalist for the Butkus Award and Lott Trophy in 2011.
In his first season at Notre Dame, Diaco switched defensive schemes from a blitzing 4-3 defense the Irish utilized in 2009 and instilled a 3-4 no-crease defense.
Diaco's defense was drastically better than the 2009 Notre Dame defense. The Irish allowed 5.69 fewer points per game, 40.5 fewer yards per game, averaged one half sacks more per game and forced more turnovers in 2010 than 2009.
The 2010 defense was dramatically improved compared to the 2009 defense in almost every statistical category: scoring defense (from 63rd in '09 to 23rd in '10), pass efficiency (82nd to 25th), rushing defense (89th to 50th) and total defense (86th to 50th).
In the final three games of the regular season, Diaco's defense limited teams averaging at least 31 points per game to 22 combined points - the fewest points allowed by a Notre Dame defense in three straight games since the 1993 season.
Only four touchdowns were scored against the Irish defense in the final five games of the regular season.
Working with the inside linebackers, Diaco helped turn Te'o into an All-America candidate in 2010. The Bednarik Award and Butkus Award semifinalist led the Irish with 133 tackles and posted 9.5 tackles for loss as a sophomore.
In his only season at Cincinnati, he was charged with replacing 10 starters on the Bearcats' defense, including every player on the front seven for 2009.
The Bearcats recorded 110 tackles for loss in 2009 (8.46 per game) to rank third in the nation. They totaled 37 sacks and tied for 10th in the country averaging 2.85 sacks per contest. Cincinnati's defense allowed 3.6 rushing yards per carry.
Focused on the inside linebackers in 2009 at Cincinnati and helped Andre Revels and JK Schaffer experience career years in their first seasons as starters. Revels led the Bearcats with 108 tackles and added 4.5 tackles for loss and one interception, while Schaffer ranked second on the team with 100 tackles with 5.5 tackles for loss, 1.5 sacks and three interceptions.
Safety Aaron Webster was named first-team all-BIG EAST in 2009 after pacing Cincinnati with four interceptions and five pass breakups. Defensive end Ricardo Mathews was named second-team all-BIG EAST as a first-year starter after he recorded a team-best 12.5 tackles for loss.
Prior to Cincinnati, spent three years as the linebackers coach and special teams coordinator on Al Groh's coaching staff at the University of Virginia from 2006-08.
At the conclusion of the 2008 season, was promoted to the Cavaliers' defensive coordinator position, but he left two months later to take the same position at Cincinnati.
Diaco's linebackers were critical to Virginia allowing only 3.7 yards per carry and just over 21 points per game to their opponents in 2008.
Only four schools permitted fewer rushing touchdowns than Virginia's nine in 2007, and the Cavaliers allowed 106.9 rushing yards per game, 13th in the nation. Virginia ranked 16th nationally at 19.7 points allowed per game and were 23rd in total defense, allowing 332.5 yards per game.
Served as co-defensive coordinator and linebackers coach under Brian Kelly at Central Michigan in 2005.
In his only season with the Chippewas, Diaco turned around Central Michigan's rushing defense that just two years earlier had ranked last in the Mid-American Conference.
Under Diaco's watch, Central Michigan led the MAC, allowing only 113.7 rushing yards per game. He also helped defensive end Dan Bazuin lead the nation with 26.5 tackles for loss and tie a MAC record with 16 sacks.
In 2004, coached the special teams and linebackers at Western Michigan. The punting, punt return and kickoff return units all finished in the top three of the MAC.
First full-time position was at Western Illinois where he was the running backs coach and special teams coordinator in 1999 and 2000. The Leathernecks won the Gateway Conference crown in 2000 and made an appearance in the NCAA Division I-AA playoffs.
Twice an all-Big Ten selection at Iowa under Hall of Fame coach Hayden Fry and was named team's co-MVP in 1995.
Led the Hawkeyes in tackles in both 1994 and 1995 and finished his career as the seventh-leading tackler in Iowa history with 334 career stops. Started all 23 games during his final two seasons.
LB Manti Te'o (Notre Dame)
2012 winner of Nagurski Trophy, Lott Trophy, Butkus Award, Lombardi Award, Bednarik Award, Maxwell Award and Walter Camp Player of the Year.
2012 Heisman Trophy runner-up
2011 finalist for Butkus Award and Lott Trophy
S Aaron Webster (Cincinnati)
2009 first-team all-Big East
LB Clint Sintim (Virginia)
Led nation in sacks by a linebacker in 2007
DE Dan Bazuin (Central Michigan)
Led nation in tackles for loss in 2005; Second-round NFL draft pick in 2007 by Chicago Bears