NWSL adopts rule changes to heat, substitution and fan policies ahead of Challenge Cup
One of the changes — developed in consultation with the NWSL Players Association, clubs, medical and competition staff and the Professional Referee Organization (PRO) — will see a new off-field treatment rule and a timed substitution rule. Additionally, the NWSL will update its game day heat safety policy and expand its fan code of conduct to cover digital and social media spaces.
Under the new off-field treatment rule — the most significant on-field change, mirroring a rule introduced at this summer’s World Cup — players who remain on the ground and require medical personnel to enter the field after play is stopped will be required to leave the field for a one-minute treatment period. This rule was previously used in Major League Soccer. The clock begins once play restarts, with the fourth official monitoring the countdown before the player is permitted to return.
The league said the measure is designed to reduce unnecessary stoppages and improve match flow.
The NWSL will also implement a timed substitution rule aimed at discouraging time-wasting. Players being substituted will now have 10 seconds to leave the field. Failure to do so will result in the incoming substitute being delayed from entering until the next stoppage after a one-minute waiting period. This would force the offending team to temporarily play down a player. Exceptions include an injury that occurred as a result of a yellow or red card offense, a head injury or injury to a goalkeeper or bleeding.
The rule arrives as leagues and competitions around the world continue searching for ways to increase active playing time and limit gamesmanship late in matches.
Player welfare also remains at the center of the league’s latest adjustments.
Following consultations with players and clubs, the NWSL has simplified its heat safety procedures. Instead of its previous two-tier system, in which the length of mandatory hydration breaks was determined by the wet bulb globe temperature (WBGT) readings, and could last up to five minutes, the new protocol states that when the WBGT falls between 82.3°F and 92.1°F, the game will be paused for 150-180 seconds. Any WBGT reading above 92.1°F will trigger a full game delay, as was the case with the league’s previous protocol.
WBGT measures multiple factors, including air temperature, humidity and wind speed, to calculate how the body experiences heat rather than just the air temperature.
The two and a half to three minutes cooling break timing is in line with what has been used at the men’s World Cup this summer. However, the 2026 tournament mandates a hydration break each half, regardless of the temperature.
The league’s heat protocols have been under increased scrutiny since last summer, when a regular-season match between the Kansas City Current and Orlando Pride was delayed by more than three and a half hours because of extreme temperatures in Kansas City.The incident reignited a broader debate about the viability of midafternoon kickoffs during the summer in the United States, particularly as broadcasters continue to favor television-friendly windows.
Off the field, the league is also expanding its “fan code of conduct” to formally include digital spaces. The new “digital code of conduct” prohibits online threats, harassment, discriminatory language and abuse directed toward players, officials, clubs and fellow supporters.
The move comes as professional sports leagues continue grappling with rising levels of online abuse aimed at athletes and match officials. By extending conduct standards beyond stadium gates, the NWSL becomes one of the few professional leagues in North America to explicitly incorporate digital behavior into its fan policy framework.
League officials distributed guidance on the changes to clubs, PRO and the NWSL Players Association during the June international break, with implementation scheduled to begin during this weekend’s Challenge Cup matches.
This article originally appeared in The Athletic.
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