Football’s lawmakers have approved trials for concussion substitutes from January for any league that wants them.
The new rule means permanent substitutions can be made if a player suffers a head injury, even if all replacements have already been used.
To avoid potential abuse of the rule, opposition teams will also be able to make a change at the same time.
The International Football Association Board (Ifab) also confirmed an extension to the five-substitute rule.
Ifab, the body that makes and approves the laws of football, originally allowed teams to make five substitutions to help with the congested schedule after football was halted by the coronavirus pandemic.
The extension, announced after a meeting on Wednesday, applies to domestic competitions ending by 31 December 2021 and for international competitions ending by 31 July 2022.
The Football Association said it welcomed the approval of an “additional permanent head injury substitute” and would implement the trials “at the earliest practical opportunity” this season in the FA Cup, Women’s FA Cup, the Women’s Super League and Women’s Championship.
John Stiles, whose World Cup-winning father Nobby died in October, having had dementia and prostate cancer, has been critical of the way that football has dealt with head traumas and injuries.
He referred to the incident in which Wolves striker Raul Jimenez suffered a fractured skull in a clash of heads with Arsenal defender David Luiz during a Premier League match at Emirates Stadium on 29 November.
Brazil centre-back Luiz played on with a bandage wrapped around his head before being substituted at half-time. Arsenal said protocols were followed regarding the decision.
Stiles said of the trials: “It’s been a long time coming. I think there’s been a general reluctance from football in general, particularly within the FA, to acknowledge there’s even a problem, and I don’t think they’ve done enough or acted quickly enough.
“And it takes an horrific incident like the one involving Luiz and Jimenez to make them actually do something.”
The Premier League is also thought to be in favour of the new law but any change to protocol in the top flight is subject to a vote by clubs, who meet on Thursday.
Concussion substitutes were set to be introduced at the football competitions of the 2020 Tokyo Olympics before the Games were postponed until 2021 because of coronavirus.
The ability to gather a more accurate diagnosis of head injuries has been in the spotlight after several members of England’s 1966 World Cup-winning team were diagnosed with dementia.
Stiles and Jack Charlton, who both died earlier this year, had dementia, while Sir Bobby Charlton’s family recently revealed he had been diagnosed with the disease.
Former Tottenham defender Jan Vertonghen also recently explained how he had felt the effects of a concussion he sustained playing for Spurs for the following nine months.
Brain injury charity Headway says that additional permanent substitutes, rather than temporary replacements as seen in rugby union, may mean that very little changes.
Headway chief executive Peter McCabe said: “Rather than celebrating this development, we’re left to question what difference this will actually make.
“The key questions are, how will players be assessed for suspected concussion, and how will decisions be made about whether they should be permanently removed?
“If decisions continue to be made in the same way, it is very hard to see how player welfare will be improved.”
‘Some refs have lost the spirit of handball’
On Wednesday, Ifab also addressed concerns regarding the interpretation of the handball law.
Former Premier League referee David Elleray, now technical director for Ifab, has admitted there have been problems with the interpretation.
Before the start of the season, Ifab tightened up the interpretation of the law, defining the boundary between the shoulder and the arm as the bottom of the armpit, and declaring that playing with ball anywhere on the arm below that constituted a handball, regardless of intent.
Ifab also emphasised a handball offence takes place when a player makes their body ‘unnaturally bigger’ and/or puts their arms above shoulder height.
It was also clarified that an “accidental” handball by an attacking player is only penalised if it occurs “immediately” before a goal or clear goal-scoring opportunity.
“It is clear there have been some high-profile incorrect decisions wrongly been portrayed as the law being wrong, when it actually was VAR getting it wrong,” Elleray said.
“In 2019, we were not asked to change handball but give more instructions to referees and detail in the law. Some refs have taken that too literally and lost the spirit of handball.”
Elleray said no imminent changes would be made but the matter would be addressed again in the spring.
He added that no discussions had taken place on the length of time taken to make some decisions with VAR. He said it was “clear VAR has had impact on the flow of the game, but it’s clear VAR has made it fairer”.
He added: “Some of the other benefits are less well publicised but there is evidence of a reduction in simulation in the area and a reduction in mobbing and arguing with refs because they know it will be checked. Behaviour is better.”