Tuesday 27 March 2018 19:34, UK
A fourth substitute can be selected in extra-time in the Champions League and Europa League competitions from next season.
UEFA has introduced new rules that also allow 12 substitutes to be selected from in the finals of both competitions, as well as that of the UEFA Super Cup.
The governing body says this is to give "coaches more flexibility regarding substitutes, and facilitate their squad management for the most important fixture of the season".
It means the squads for finals will rise to 23 players. The squads for all other games will remain at 18 players including seven subs.
A number of managers have spoken of a desire to be able to select from more substitutes in recent years, including Claudio Ranieri during his time as Leicester City manager.
UEFA have also altered kick-off times for the 2018-19 season, with matches beginning at 7pm and 8pm UK time on Tuesday's and Wednesdays.
