[3] Hager attended and played high school football at Westlake High School,[4] where his teammates included future NFL quarterback Nick Foles and kicker Justin Tucker.

[6] Hager was selected by the St. Louis Rams in the seventh round, 224th overall, of the 2015 NFL draft.

The 224 overall pick was traded to the Rams by the New York Jets in exchange for Zac Stacy.

[13] He was elevated to the active roster on October 24 and October 31 for the team's weeks 7 and 8 games against the Buffalo Bills and Kansas City Chiefs, and reverted to the practice squad after each game.

[16] Hager has a younger brother named Breckyn who played linebacker for the Texas Longhorns.