The participating clubs are listed in the following table: The total number of foreign players is restricted to five per club.
Clubs can register up to four foreign players for a single match-day squad, of which a maximum of three are allowed from nations outside the Asian Football Confederation (AFC).
Players from J.League partner nations (Thailand, Vietnam, Myanmar, Cambodia, Singapore, Indonesia, Iran, Malaysia, and Qatar) are exempt from these restrictions.
Thus, Yokohama FC, finishing third in the season, received a bye into the second round, from which the winner will play the team finishing 16th in J1.
League DataNotes:† Relegated from J1.‡ Promoted from J3.