[1] After recording 48 tackles and five interceptions as a sophomore, Sewell missed his entire junior season after suffering a broken neck in his first game of that year.
[3] He saw immediate playing time as a true freshman, being named the school's player of the week in his debut, where he recorded five tackles at safety.
[1] Sewell changed his position from safety to linebacker for the 2020 season,[5] and placed second on the team with 40 tackles, while starting all five of their games.
[1] He had three games with more than 10 tackles and ranked eighth in the conference for average tackles-per-game with 6.8, being named first-team all-conference by Associated Press (AP).
[11] He was promoted to the active roster on November 10,[12] and made his NFL debut in the Saints' 20–10 loss to the Pittsburgh Steelers in Week 10.
In New Orleans' season finale against the Tampa Bay Buccaneers, Sewell recorded his first career sack against Baker Mayfield.