FIFA will trial deputies for actual or suspected concussion at the Club World Cup in Qatar next month.
Each team will be able to use one concussion replacement per game with the switch able to occur regardless of the number of changes already made.
This will be the first international competition to trial the bid.
Teams can use five custom substitutes per game but to avoid disruption they will only have three opportunities to make changes, as well as half time.
Tigres from Mexico, Egyptian club Al Ahly, Bayern Munich from Germany, Ulsan South Korea, Auckland City from New Zealand, welcome Al Duhail and the winners of the Copa Libertadores South America will compete for the title next month.
The introduction of concussion substitutes has been proposed as a measure to help address football’s growing concern over dementia.
Campaigners have been calling for changes in the way the game is played after several former players were diagnosed with dementia, which has been linked to football heads.
Some football associations have already banned headlining in games or coaching children.
The Association of Professional Footballers is setting up a task force to look into the issue.
BBC Sport understands that the Premier League is awaiting final protocols for how concussion substitutes might work in the English game before deciding with clubs when it will start its own trial.
The FAW also remains keen to implement the trials at the earliest opportunity.
It is thought that teams could use concussion substitutes in the fourth round of the FA Cup, which is due to run over the weekend of January 23-24. (BBC Sport)