Mast spent four years at Bradley University, totaling 1,001 points and 657 rebounds in three seasons after redshirting in 2019-20 because of an injury. Last season, Mast earned first-team All-MVC honors, leading Bradley in scoring (13.8 ppg) and rebounding (8.0 rpg) while shooting 51 percent from the floor and 35 percent from 3-point range. He ranked second in the MVC in rebounding, fourth in field goal percentage and 11th in scoring, as he finished third in voting for MVC Player of the Year. Mast, who also averaged 2.4 assists per game, totaled nine double-doubles, including 14 points and 12 rebounds in Bradley’s NIT loss to Wisconsin. He had a career-high 30-point effort against Northern Iowa in the MVC Tournament, one of 26 double-figure scoring efforts last season.
Mast earned third-team All-MVC and second-team NABC All-District 16 honors in 2021-22, averaging 11.6 points and 8.4 rebounds per game as he topped the conference and ranked in the top 50 nationally in rebounding. He totaled nine double-doubles and had 18 double-figure contests in 2021-22. Mast had five 20-point games, including a season-high 23 points and 13 rebounds against Evansville and 20 points and 14 rebounds in a win over Indiana State to garner MVC Player of the Week. He was named to the MVC All-Freshman Team in 2020-21, as he played in 28 games and averaged 8.6 points and 5.8 rebounds per game. His year was highlighted by a 24-point, 10-rebound effort against Southern Illinois in the MVC Tournament. In that game he was 10-of-16 from the floor, including four 3-pointers.
Before coming to the United States, Mast earned all-star team honors at the 2017 FIBA European Under-16 Championship after leading the Netherlands to a second-place finish in Division B. He also served as captain a year later at the 2018 European Under-18 Championship, helping Holland to the Division B title. Mast played for Donar in the top division of the Dutch Basketball League and was named the league’s Youth Player of the Year and Most Improved Player following the 2018-19 season. While at Donar, he was teammates with former Huskers Lance Jeter and Jason Dourisseau.