Leeds maintain their medical staff adhered to the Premier League’s concussion protocols after Robin Koch sustained a head injury during the home defeat against Manchester United on Sunday but indicated they would endorse any future use of temporary substitutes in similar circumstances.

Although the potential introduction of such short-term replacements is expected to be discussed at the AGM of Ifab,on Thursday 3 March, football’s international law-making body, has previously been cool on the idea and the Premier League is powerless to act without its approval.

Leeds have come in for criticism for the decision to permit Koch to play on for 15 minutes after a clash of heads with Scott McTominay. The Professional Footballers’ Association claimed the top tier’s existing protocols were “failing to prioritise player safety” as it joined the brain injury charity Headway in advocating the introduction of concussion substitutes.

Koch sustained a cut near an eye but swiftly returned to the pitch with his head heavily bandaged before sitting down on the turf 15 minutes later and signalling he could not continue. The delay in the defender’s departure appeared in contravention of Football Association guidelines adopted by the Premier League that state that any player who sustains a suspected concussion should immediately be removed from pitch.

Leeds dispute this view and, despite confirming that Koch would not be involved at Liverpool on Wednesday, said: “Robin Koch passed all the on-field concussion screening tests that are currently part of the Premier League protocols,” it read. “The player was told that, if he developed any symptoms, he should sit down on the field of play and would be substituted immediately, which is what Robin did.”

As part of an Ifab trial, the introduction of extra permanent substitutions are allowed in such instances, but the deployment of temporary concussions replacements would allow injured players to be fully evaluated before an informed decision about their fitness was made.

Ifab is likely to face calls to trial temporary concussion substitutes but it has previously resisted the idea, arguing they would make little difference because the onset of concussion symptoms is often delayed. Moreover, most club doctors lack expertise regarding brain injuries, dictating the deployment of an extra permanent substitute is safer.

Leeds disagree. “The medical staff at Leeds have always been in favour of temporary substitutions for head injuries as it would allow a period for symptoms to potentially develop,” they said. “Robin will now follow the concussion protocols before returning to play.” On Sunday Marcelo Bielsa, the Leeds manager, said Koch was withdrawn purely because of blood loss from the cut.

The PFA believes the guidelines are being interpreted too loosely. “The current protocols are failing to prioritise player safety,” the players’ union said. “The ‘if in doubt, sit them out’ protocol is not being applied consistently within the pressurised environment of elite competitive football. We have been clear to Ifab that we want to see the introduction of temporary concussion substitutes.

“They would allow a match to restart with neither side numerically disadvantaged, reducing pressure on players and medical teams to make quick decisions. The current rules set by Ifab are not working; players are being put at risk.”

Headway’s deputy chief executive, Luke Griggs, said: “The game has to help medics by implementing temporary concussion substitutes. We need urgent answers from the Premier League as their reputation is on the line here.”

Koch thanked the Leeds medical staff for “the good care”, tweeting that he felt “much better” and would “be back soon.”