Mason played college football at Georgia Tech, positioned as a running back from 2017 to 2021.
[5] On December 15, 2022, Mason iced the game against the Seattle Seahawks with a 56 yard run, which also guaranteed the 49ers would win the NFC West.
[10] In week one of the 2024 NFL season, Mason replaced Christian McCaffrey in the starting lineup and ran for 147 yards and one touchdown in a win against the New York Jets.
[11] In Week 5, he had 160 scrimmage yards and a rushing touchdown in a 30–13 win over the New England Patriots.
[12] In Week 6, Mason exited the matchup against the Seattle Seahawks with a shoulder injury.