NEW YORK – Major League Soccer Thursday announced that a fourth substitute will be available to teams during the Audi 2017 MLS Cup playoffs and 2017 MLS Cup for postseason matches that require the two, 15-minute extra -time periods.

An update to the MLS disciplinary committee parameters also has been introduced for incidents involving Video Review.

The International Football Association Board , which oversees changes to the Laws of the Game, has approved experiments with a fourth substitution during extra time.

Under the IFAB parameters, a fourth substitute may only be used if a game goes to extratime and may be used regardless of the number of substitutes a team made during regulation time. Other competitions that have experimented with the fourth substitute include the English FA Cup, Scottish Cup, FIFA Confederations Cup and the FIFA Club World Cup.

The IFAB will make a final decision about incorporation of the fourth substitute in 2018 or 2019.

Additionally, in conjunction with the implementation of video review, the disciplinary committee has amended its third parameter.

That’s when the referee sees an incident and does not issue a red card. Under the amended third parameter, if the incident on the field was checked by the Video Assistant Referee regardless of a review by the on-field referee, the disciplinary committee will only act in instances that warrant at least a two-game suspension.

If a play is not checked by video review, the disciplinary committee maintains the authority to issue supplemental fines and/or suspensions.

The disciplinary committee will continue to act on incidents in which the referee or VAR does not see the incident, or where the referee sees an incident and issues a red card. Misconduct that lies outside the video review protocol such as, but not limited to, simulation/embellishment, mass confrontation, public criticisms, and use of offensive, insulting or abusive language, will be adjudicated according to the current disciplinary parameters.

Commissioner Don Garber can issue supplemental discipline, including fines and suspensions, if he determines on-field misconduct has occurred or if off-field misconduct is deemed detrimental to the reputation and public image of MLS.