Sean Duggan

Coaching career Boston College Duggan started his coaching career with Boston College as a defensive graduate assistant for one year.

Hawaii After Boston College, Duggan would take a coaching position at Hawaii as the team's linebackers coach. During the 2017 season while coaching a game against Western Carolina, Duggan suffered a bizarre injury as when Viane Moala blocked a field goal, Duggan celebrated with Moala by chest bumping him. However Moala would knock Duggan to the ground dislocating his elbow and fracturing his wrist.

UMass After two years with Hawaii, Duggan would move on to UMass to be the linebackers coach.

Ohio State After one year with UMass, Duggan would leave for Ohio State to become a graduate assistant.

Boston College (second stint) After one season with the Buckeyes, Duggan would return to Boston College as the team's linebackers coach. In the 2021 season as the linebackers coach for Boston College, Duggan would be named a top 30 coach under the age of 30 by 247Sports. After two season as the linebackers coach for Boston College, Duggan would be promoted to co-defensive coordinator while also maintaining his linebacker coaching position.

Green Bay Packers On January 31, 2024, Duggan's head coach at Boston College, Jeff Hafley, was hired by the Green Bay Packers to be their defensive coordinator. On March 12, Duggan was hired as a defensive assistant by the Packers.

On February 3, 2025, linebackers coach Anthony Campanile was hired by the Jacksonville Jaguars to be their defensive coordinator. Packers defensive coordinator Jeff Hafley subsequently named Duggan as the Packers' new linebackers coach.

Miami Dolphins On January 29, 2026, Duggan followed Hafley to the Miami Dolphins to serve as the team's defensive coordinator.