IFAB (international football Association Board, which approves the rules of the game) supported the initiative of FIFA about extending the provisions of regulation 5 substitutions per team in a match.
This permission was introduced after completion of the quarantine breaks and worked until the end of 2020, and now extended to the end of season 2020/21.
In addition, each football League and the tournament can make the decision whether to impose the rule 5 substitutions or to leave the usual 3 substitutions per team in a match.
Coaches can spend 5 substitutions, but only three slots.
The FDA previously approved the rule and allowed 5 substitutions.