Rountree attended Millbrook High School in Raleigh, North Carolina.

[3] As a true freshman at Missouri in 2017, Rountree played in all 13 games and rushed for 703 yards on 126 carries with six touchdowns.

[9][10] Rountree was selected in the sixth round (198th overall) in the 2021 NFL draft by the Los Angeles Chargers.

[14] He scored his first NFL touchdown on a one-yard rush in a Week 10 game of the 2021 season against the Minnesota Vikings.

[24] On January 19, 2024, Rountree signed with the Birmingham Stallions of the United Football League (UFL).