REUTERS: The Professional Footballers' Association (PFA) and FIFPRO, the global players' union, have called on football's lawmakers to consider launching trials into temporary concussion substitutes to better protect players who suffer head injuries.
The game's rule-making body IFAB in December gave the go-ahead for trials of permanent concussion substitutes following which the Premier League and Women's Super League introduced the system in February.
According to the league's protocol, team doctors make an assessment of the player who suffers a head injury and if the player shows clear symptoms, they will be substituted and prevented from returning to the field.
But concerns have been raised after West Ham United defender Issa Diop and Sheffield United defender George Baldock were allowed to continue playing after sustaining head injuries.
PFA and FIFPRO, in a letter to IFAB on Thursday, said temporary substitutes, which would allow a player to be replaced while the doctor examines them but return if deemed fit to continue, better protects player health and reduces pressure on medical staff to make snap decisions.
"Since the beginning of IFAB's permanent concussion substitute trial, we have seen several incidents where the new laws of the game have fallen short of their objective and jeopardised player safety," the letter stated.
"We ask for the existing trial to be extended in order to test in parallel temporary concussion substitutions.
"In England... we are aware of two incidents where a temporary option would have better protected players. These cases underline our concern that permanent subs do not give medical teams appropriate environment to assess a player."
The letter also referenced a poll of 96 professional club doctors from the Belgium, English and French leagues, which found that 83per cent believe the use of temporary concussion substitutions should form a part of future protocol.
Head injury specialist Willie Stewart last month described the trial of permanent concussion substitutes as a "shambles", and the system was also criticised by former Newcastle United striker Alan Shearer.
(Reporting by Arvind Sriram in Bengaluru, editing by Pritha Sarkar)