2019: 17 GP, 5 GS, 1 G, 0 A in 493 min.
Signed with Bethlehem Steel FC on April 5, 2019. Borgelin made a substitute appearance in the match against Birmingham (March 10), making his debut for Steel FC. He also appeared as a substitute in the matches against Memphis (March 24), Pittsburgh (March 30) and Charleston (April 13). Borgelin made his first-professional start in the match against Indy (April 20) and also started in the match against Atlanta (May 12). He made a second-half substitute appearance in the match against Ottawa (May 19) and then came on as a sub in the first-half of the match at Red Bulls II (May 31). Borgelin returned to the starting lineup in the match against Nashville (June 9) and then made a second-half substitute appearance in the match against Saint Louis (June 15). He started in the match against Tampa Bay (June 22) and made substitute appearances in the matches at Hartford (June 28), Pittsburgh (July 4), Louisville (July 20) and Saint Louis (July 27). Borgelin returned to the starting lineup in the match against Hartford (August 1). He made a substitute appearance in the match at North Carolina (September 7), scoring his first professional goal in the match.
2017-2019 (Union Academy): Borgelin spent two years in the Philadelphia Union Academy’s Residency Program and played two seasons with the Academy’s U16/17 and U18/19 squads. Over the course of his two seasons with the Academy, he made 39 appearances, 19 starts and scored 14 goals in the 2017-2018 and 2018-2019 seasons.