Mack grew up in Fort Wayne, Indiana, and attended Bishop Luers High School.

[3] Rated a four-star recruit and the best collegiate prospect in Indiana by Rivals.com, Mack committed to play college football at Ohio State going into his senior year over offers from Notre Dame, Michigan, and Tennessee.

[4] Mack was a member of the Ohio State Buckeyes for four seasons and joined the team as an early enrollee.

[9][10] Mack signed with the New York Giants as an undrafted free agent on April 25, 2020, shortly after the conclusion of the 2020 NFL draft.

[14][15] On October 3, Mack was elevated to the active roster, but he was listed inactive for the team's game the next day against the Los Angeles Rams and was subsequently reverted to the practice squad.

In his first year in the CFL, Mack played in 17 regular season games where he had 78 receptions for 1,154 yards and four touchdowns.

In the 110th Grey Cup, Mack led all receivers with six receptions for 103 yards and one touchdown as the Alouettes defeated the Winnipeg Blue Bombers 28–24.