Duggan began playing youth football at age five with Kirchheimer SC, where he played until moving to FC Ismaning in 2017.[1][2]
College career
In 2021, he moved to the United States to attend college, initially set to attend Francis Marion University, however, due to not meeting certain academic requirements, he was deemed ineligible and instead transferred to Iowa Lakes Community College.[3] He helped Iowa Lakes win the 2021 Midwest District Championship and was named an All-Region Honorable Mention.[4][5]
In 2022, he transferred to Marshall University to play for the men's soccer team in the NCAA.[6] On 23 October 2022, he scored his first goal in a victory over the Georgia Southern Eagles.[7] Ahead of the 2023 season, he was named to the Preseason All-Sun Belt Conference Team and named team captain.[8][3] At the end of the season he was named the Sun Belt Conference Defensive Player of the Year and was named to the All-Sun Belt Conference First Team.[9] He was also named a First Team All-American and finished as a Mac Hermann semifinalist.[10][11] He was also invited to participate in the MLS College Showcase.[12]
At the 2024 MLS SuperDraft, Duggan was selected in the third round (67th overall) by Minnesota United FC.[17][18] He initially missed the start of training camp with the club, due to visa issues, but was eventually able to arrive.[19][20] In February 2024, he signed a one-year contract with the club, with club options for the next three seasons.[21] He made his Major League Soccer debut for the first team on June 8 against FC Dallas.[22] He spent the majority of the season with the second team, Minnesota United FC 2 in MLS Pro,[23] before being loaned to USL Championship side Rhode Island FC for the remainder of the 2024 season.[24][25]