[2] On March 29, he made his professional debut for USL affiliate club Portland Timbers 2 in a 3–1 victory over Real Monarchs SLC.
[3] Besler signed with United Soccer League side Real Monarchs on January 2, 2017.
[4] He scored his first goal for Real Monarchs on March 28, 2017, in a 2–1 victory against his former club Portland Timbers 2.
On August 24, 2017, Besler was signed to the Monarchs' Major League Soccer parent club Real Salt Lake.
[7] He is the younger brother of Matt Besler, a retired soccer player who played for Sporting Kansas City and Austin FC.