A number of Premier League clubs believe that permanent concussion substitutions are not fit for purpose and that a ‘tipping point’ has been reached following the sickening head injury to Leeds defender Robin Koch.
Sportsmail understands that a growing group - including Leeds and Chelsea - want rulemakers to instead introduce temporary replacements and feel that, under the current rules, players remain at risk.
Their views have been communicated to the top flight and are likely to be passed on to the International Football Association Board, which has been overseeing the trial of permanent concussion subs since it began in February last year.