UEFA, the sport's governing body in Europe, have issued a rule change that will allow for an extra substitution during UEFA Champions League and Europa League knockout ties.
Whether a team is playing in the Champions League or Europa League knockouts, they will be allowed to make a fourth substitution if the game goes into extra time.
And for the teams that make the final of the competitions each year, they will have the chance to name 12 players on the substitutes bench. It means the entirety of a team's 23 man squad could theoretically play a part in the game after it kicks off.
There will also be some changes to kick off times from the 2018-19 season, with games starting at 7pm and 8pm UK time in midweek.