Section 4: Players & Officials
Squad and Match Roster
- Each MLS club selects a match-day roster of up to 20 players (11 starters and 9 named substitutes)
- Senior roster construction, international slots, allocation money, and salary mechanics are governed by the separate MLS Roster Rules & Regulations
Substitutions — Regular Season
- Each club may make up to 5 normal substitutions per match (excluding half-time and re-entry of the same player as a substitute)
- Substitutions must be used over a maximum of 3 substitution opportunities ("windows") plus half-time
- One additional concussion substitution per match is permitted to remove a player with an actual or suspected concussion (IFAB Law 3 trial)
- Any player being substituted out has a maximum of 10 seconds to leave the field of play
Substitutions — Audi 2026 MLS Cup Playoffs
- Maximum 5 normal substitutions plus 2 concussion substitutions per playoff match
- Unused substitutions carry over into extra time; no additional substitution opportunities are added for the extra-time periods
Officiating Crew
Each MLS match is officiated by a referee, two assistant referees, a fourth official, a Video Assistant Referee (VAR), and at least one assistant VAR. The referee on the field has final on-field authority. VAR is operative for clear-and-obvious-error reviews of (a) goals and surrounding incidents, (b) penalty decisions, (c) direct red-card incidents, and (d) cases of mistaken identity, in line with the IFAB VAR Protocol. The referee announces VAR-final decisions to fans in the venue and to the broadcast.
Bench Composition
- Maximum 19 individuals on each bench: 9 named substitute players, 9 staff members, 1 club physician
- Two Certified Athletic Trainers (ATCs) must be on the bench
- Coaches/staff/substitutes who leave the bench to egregiously protest an official's decision or express dissent face fines and/or suspensions (Section 7)