Mathis was rated a three-star recruit and initially committed to play college football at South Carolina.
[2] Mathis played in nine games as a freshman, appearing mostly on special teams.
[4] He suffered a non-football related shoulder injury prior to his senior season and used a medical redshirt.
[5] In his fifth season, Mathis played in 13 games and had 44 tackles, with six passes broken up and two interceptions, one of which he returned for a touchdown, and was named honorable mention All-Atlantic Coast Conference.
[12] On August 27, 2024, Mathis was placed on short-term injured reserve by the Broncos ahead of the 2024 NFL season.