A four-star recruit and the top ranked player in the state of South Carolina heading into Alabama,[1] Miller was primarily used as an outside linebacker in college, although coach Nick Saban sometimes experimented with him at inside linebacker in practice due to his versatility.

[1] Miller's junior season was widely hampered by injuries, but was highlighted with a sack in the 2017 College Football Playoff National Championship.

Unfortunately, Miller strained his hamstring in the 2018 Orange Bowl and missed the 2019 College Football Playoff National Championship game due to the injury.

[2] At the 2019 NFL Scouting Combine, Miller recorded a 38.5-inch vertical jump and had the longest arm length measured for a linebacker at 35 1/8.

[3] In week 3 against the Arizona Cardinals, Miller recorded his first 2 career sacks on fellow rookie Kyler Murray in the 38–20 win.