Teams will be allowed to make up to five substitutions per match if and when football does return this season.
The International Football Association Board (IFAB), who govern the laws of the game, have made a temporary amendment to Law 3 off the back of a request from FIFA, with protecting player welfare at the centre of their concerns.
Any competition that has already started but is due to finish by the end of this year can implement the law to increase from three permitted subs to five for each team in their remaining fixtures.
The law is conditional on it being implemented by the respective governing bodies of specific competitions, e.g. UEFA agreeing for its use in the Champions League.
One objection to passing the amendment initially was the suggestion that teams may use it to their advantage to time waste.
However, IFAB have stated that teams can only make changes at three times during a match, or at half-time, in order to minimise disruption.
A statement from IFAB on Friday said: "The temporary amendment comes into force with immediate effect, and has been made as matches may be played in a condensed period in different weather conditions, both of which could have impacts on player welfare.
"The decision on whether to apply this temporary amendment will remain at the discretion of each individual competition organiser, while The IFAB and FIFA will determine at a later stage whether this temporary amendment would need to be extended further (e.g. for competitions due to be completed in 2021)."
IFAB's ruling now leaves the decision in the hands of the FA, as well as the Premier League and EFL, as to whether they want to utilise it in English football.
The law could also impact Champions League and Europa League football, depending on how UEFA wish to proceed with those competitions.
Should teams make substitutions at the same time, that would only classify as one opportunity for each team.
If matches go to extra time in cup competitions where the law is in place, substitutions will be carried over as normal.
In competitions where an additional substitution is permitted in extra time - like the Champions League - this will remain the case, with teams able to also make changes after full-time and at half-time in extra time.