Leslie Frazier's portfolio with the Buffalo Bills has widened.

The club announced on Wednesday that their defensive coordinator had been given the additional title of assistant head coach.

"Upon taking the job in Buffalo, it was important to me to add a coach with previous head coaching experience like Leslie," head coach Sean McDermott said in a release. "His fingerprints are all over our operation and I'm extremely grateful for all the years we have worked together. Leslie's impact on our team is felt every day through his guidance, wisdom, and his genuine care for people. He is a great example to everyone within our organization."

The 60-year-old Frazier is heading into his fourth season as the Bills' DC and enters his fourth decade of coaching in the league.

Prior to joining the Bills, he spent four seasons as head coach of the Minnesota Vikings from 2010 to 2013 and held coaching and coordinating positions with the Philadelphia Eagles, Cincinnati Bengals, Indianapolis Colts, Tampa Bay Buccaneers and Baltimore Ravens.

Last season under Frazier, the Bills' defence was third overall in the NFL, second in points allowed, 10th against the run and fourth against the pass and the team reached the postseason for the second time in three seasons following a playoff drought of 17 seasons.

"I'm definitely pleased and honored that Sean along with Kim and Terry would feel moved to place that title alongside my name," said Frazier in a statement. "I don't know how much it changes my role. I feel like Sean and I communicate on so many things regarding our team. I just appreciate that our ownership along with our head coach felt the desire to put that title next to my name. Just very appreciative."