Scottish football clubs will soon be able to substitute players who receive a head injury, regardless of the number of subs already used.
From March 6, concussion substitutes will be allowed on a trial basis following a vote by the 42 clubs of the Scottish Professional Football League (SPFL).
The new rule, allowing each club to make a maximum of two concussion substitutes per match, will apply for the remainder of the 2020/21 season.
When a concussion substitute is used, the opposing team has the option to use an additional substitute for any reason.
The news comes a day after it was revealed that former Scotland defender Gordon McQueen has been diagnosed with vascular dementia.
Heading the ball and head injuries have been linked to dementia by a number of studies.
SPFL chief executive Neil Doncaster said: “The safety and wellbeing of players is clearly of the utmost importance to everyone involved with running football.
“Yesterday’s tragic news that Gordon McQueen has been diagnosed with dementia is the latest reminder of why it is vital that we do everything we can to protect those playing our game.
“We have seen a great deal of positive development in concussion protocols across sport in recent years and we hope that our participation in this trial will be the next step in that process.
“The Scottish FA refereeing department has already started briefing our clubs on the details of the rule change, with that process continuing in advance of the change coming into force on 6 March.”
The SPFL say a concussion substitution may be made regardless of the number of substitutes already used.
When a head injury is sustained or suspected, the team may either use one of their existing substitutes, if the maximum permitted number have not been used, or make an additional concussion substitute.
New rules came into effect last year that banned children aged under 12 in Scotland from heading footballs during training.
Restrictions on footballers aged 12-17 were also imposed by the Scottish Football Association.
The move followed a report by Glasgow University that found former professional footballers were three-and-a-half times more likely to die of a degenerative brain disease.