MANCHESTER, England (Reuters) -Football's rule-making body IFAB has given the go-ahead for trials of additional "concussion subs" with the pilot studies cleared to begin as early as January.
FIFA has said it is ready to trial the system in next year's Olympic Games while the Premier League is reported by British media to be eager to introduce it as soon as possible.
The system would be for permanent substitutions of players with suspected concussion even if a team have used all their permitted substitutes.
However, the changes do not make provision for "temporary concussion substitutes" which some in the game had been calling for as a way for players to have more time to be checked out before returning to play.
Brain injury charity Headway said it was disappointed with the decision not to trial temporary substitutes.
"Headway has been calling for concussion substitutes for years -- and yet rather than celebrating this development, we're left to question what difference this will actually make if IFAB moves forward with permanent, rather than temporary substitutes," chief executive Peter McCabe said.
"The benefit of a temporary concussion substitution is that it allows for the player to be assessed off the pitch, in a quiet, appropriate treatment room away from the heat of battle and the glare of players, officials, coaches and fans."
IFAB said it had consulted with medical concussion experts, team doctors, player representatives, coaches, competition organisers, refereeing and laws of the game experts.
McCabe, however, doubted the trial would improve player safety.
"We know how difficult it can be for club medics to make concussion assessments on or at the side of the pitch, particularly in such a short space of time or when there are language barriers," he said.
IFAB also gave the green light to the further extension of the temporary measure for five subs per game rather than three -- brought in due to the COVID-19 related fixture congestion.
The extension applies for domestic competitions ending by Dec. 31, 2021 and for international competitions ending by July 31, 2022.
(Reporting by Simon Evans, additional reporting by Martyn Herman; Editing by Christian Radnedge and Ed Osmond)