Thierjung played four years of college soccer at the University of California, Berkeley between 2013 and 2016.
[1] While at college, Thierjung appeared for Premier Development League sides OC Pateadores Blues and Burlingame Dragons.
[2][3] On January 17, 2017, Thierjung was selected in the third round (50th overall) of the 2017 MLS SuperDraft by San Jose Earthquakes.
In April 2017, Thierjung signed with National Premier Soccer League side New York Cosmos B.
[6] He made his debut for the Roughnecks on July 22, 2017, as an 80th-minute substitute against Phoenix Rising FC, and scored in the 85th minute to give them a 3–0 victory.