[6] While in college, Gasper played with PSA Elite during their Lamar Hunt US Open Cup in 2015,[7] as well as in the Premier Development League with FC Golden State Force in 2016.
[8] On January 11, 2019, Gasper was drafted 15th overall in the 2019 MLS SuperDraft by Minnesota United FC after they traded $50,000 of GAM to the Chicago Fire to secure the pick.
[12] Gasper ended the regular season with 15 appearances, helping the Loons finish 4th in the Western Conference to qualify for the MLS Cup Playoffs for the first time in team history.
[12] Gasper also started all 5 of Minnesota's Open Cup games, helping the Loons reach the final, where were defeated 2–1 by Atlanta United FC.
[16][17] He played every minute of their 3 playoff games to help Minnesota reach the conference finals where they lost 3–2 to Seattle Sounders FC.
[27] On February 1, 2020, Gasper earned his first senior cap for the United States national team as a substitute in a 1–0 friendly win against Costa Rica.