Sirmon was selected by the Tennessee Titans in the fourth round (128th overall) of the 2000 NFL draft.
[3] He was brought in by Steve Sarkisian as his linebackers coach when Wilcox was hired by the University of Southern California as defensive coordinator.
[5] In January 2017, Mississippi State replaced Sirmon and hired Todd Grantham as defensive coordinator from Louisville.
[7] Sirmon left Louisville and moved to the University of California, Berkeley in 2018, where he is the Bears' inside linebackers coach and defensive coordinator.
[8] Alongside fellow staff member Tim DeRuyter, Sirmon was named FootballScoop's Linebacker Coach of the Year in 2019.