On Monday, Major League Soccer announced that it would be participating in FIFA’s pilot program, which would implement concussion substitutions into the game, in the 2021 season.
The pilot program will allow clubs to make a total of two substitutions throughout the match to be used on players who sustained or are suspected of having a concussion. These substitutions do not count as regular substitutions and are separate from the five substitutes in three windows.
If a team were to use a concussion substitution at any point in a game, the opposing team will be awarded an extra substitution as a result.