[1] Union II competes in the MLS Next Pro's Eastern Conference.

After taking a competitive hiatus during the 2021 season, by December 2021 Union II was announced as one of the founding clubs of MLS Next Pro.

[2] Marlon LeBlanc, who was appointed head coach of Union II in March 2021, would now have his first competitive season with the team.

[5] Largely supplemented with first team and academy players, the front office made a marquee signing with José Riasco, paying a reported transfer fee over $1 million.

[6] Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.