Section 8: Safety Considerations
Concussion Protocol
MLS operates under the league's Concussion Management Protocol, developed in conjunction with U.S. Soccer and the league medical staff. The IFAB-trial concussion substitution permits one additional substitution per team beyond the five-substitute count when a player has an actual or suspected concussion (two additional in the playoffs). A player removed under the concussion protocol cannot return to the match and is subject to a graduated return-to-play assessment before being cleared for subsequent training and competition.
Off-Field Treatment Window
The OTR rule (Section 5) is intended to reduce on-field stalling around minor injuries while preserving the priority of medical assessment. Players removed for off-field treatment under the OTR rule may return after one minute; this is distinct from the concussion-substitution pathway, which permanently removes the player.
Heat and Air Quality
Mandatory cooling breaks apply when WBGT is at or above 82°F (27.8°C). The league applies WBGT-based heat thresholds for cooling breaks, additional water breaks, and, in extreme cases, for delays of kickoff or postponement. Air-quality-index thresholds apply for venues affected by wildfire smoke or other particulate events.
Field Conditions
The home club is responsible for ensuring the field of play meets league surface standards. Lightning detection and the league lightning policy halt outdoor activity within a defined radius of detected strikes; play resumes only after the all-clear interval has elapsed.
Athletic Training and Medical Coverage
- Each match must have at least one club physician on the bench, supported by Certified Athletic Trainers
- An emergency action plan covering on-field cardiac, head/neck, and orthopedic emergencies must be in effect at every venue
- Independent league medical observers may be present for high-profile or postseason matches
Mental Health and Player Welfare
MLS provides mental-health support through the league's player welfare program in coordination with the MLS Players Association. The Player Code of Conduct, the Anti-Discrimination Policy, and related governance documents apply alongside the Competition Guidelines.