The Club World Cup and Olympic tournament will be used to test the viability of a fourth substitute during extra time.
FIFA has announced that the use of a fourth substitute during extra time will be tested at this year's Olympic Games and Club World Cup.
The International Football Association Board (IFAB) agreed at their latest meeting earlier this month to allow for the experimentation of an additional sub during matches that extend beyond the allotted 90 minutes.
"The FIFA Executive Committee agreed for such experiments to be conducted this year at the Olympic Football Tournaments, the FIFA U-20 Women's World Cup Papua New Guinea and the FIFA Club World Cup Japan," football's governing body confirmed via a release on Friday.