The use of concussion substitutes in the SPFL will be allowed on a trial basis from 6 March until the end of the season, after a vote by all 68 clubs.
Clubs will be permitted to use a maximum of two such replacements in a match, regardless of the number of substitutions already made.
The rule change follows an announcement in December that system could be trialled until August .)
- The Scottish FA refereeing department has begun to brief clubs on the rule change.
McQueen diagnosed with dementia
“Yesterday’s tragic news that Gordon McQueen has been diagnosed with dementia is the latest reminder of why it is vital we do everything we can to protect those playing our game,” said SPFL chief executive Neil Doncaster.
McQueen, 11, has been diagnosed with vascular dementia, with his family saying in a statement they wished to raise awareness.
McQueen’s former Leeds team-mate Jack Charlton died with dementia last year and it was confirmed in recent months that Sir Bobby Charlton has been diagnosed with the disease.