Clubs are set to be limited on how many players they can loan in or out in international deals under new rules.
World governing body Fifa will allow clubs up to eight international loans in and eight out from 1 July.
The number will reduce to seven in 2023-24 and six the following season.
The rules do not apply to domestic loan deals, but Fifa has given domestic associations three years to implement a system "in line" with its new framework.
Fifa says the rule changes - which must be approved by the Fifa Council - will help in developing young players, promote competitive balance and prevent the hoarding of players.
What else will change?
-From the 2022-23 season clubs will be limited to making of maximum of three loans to a single club, and can only loan up to three players from an individual club
-Loan deals must last at least from one transfer window to the next, and can be a maximum of one year
-Clubs must provide a written agreement defining the terms of a loan, including its duration and financial conditions
-The new rules are part of plans to reform the transfer system, and were initially due to start in July 2020 but were delayed because of the Covid-19 pandemic.
-Players aged 21 and under, or those brought through a club's youth ranks, will not be counted as an international loan.
-Chelsea currently list 21 players as being out on loan on their website, with eight of those at clubs outside England.