Complex sentence: In its first season, Louisville City was the official reserve side for Orlando City SC, making its debut in Major League Soccer at the same time, but that arrangement ended in 2016, when Orlando City established a directly controlled reserve side in the USL.
Split into simpler sentences: In its first season, Louisville City was the official reserve side for Orlando City SC while making its debut in Major League Soccer at the same time. That arrangement ended in 2016, when Orlando City established a directly controlled reserve side in the USL.