Brain injury charity Headway said the Premier League’s reputation was “on the line” as it claimed protocol was not followed when Leeds’ Robin Koch sustained a blow to the head in Sunday’s defeat to Manchester United.

Headway said “enough is enough” and demanded answers from league bosses after Koch was allowed to play on at Elland Road after suffering a head injury in a collision with Scott McTominay.

The Professional Footballers’ Association has also called again for the introduction of temporary substitutions for head injuries.

Leeds insist they followed the league’s protocol and that they have always supported temporary substitutions if injured players are at risk.

Headway deputy chief executive Luke Griggs said: “Yet again we are left completely frustrated and confused by football’s approach to concussion.

“Medics have a tough time when trying to make on-pitch concussion assessments. The game simply has to help them by implementing temporary concussion substitutes.

“It is hard to believe that if they had 10 minutes to assess the player in the quiet confines of the dressing room that they would have come to the conclusion that he was fit to continue.

“We need urgent answers from the Premier League as their reputation is on the line here.

“Concussion protocols in all sports clearly state ‘if in doubt, sit it out’. The Premier League needs to come out and explain to everyone – particularly impressionable youngsters and grassroots players – what the word ‘doubt’ actually means because I think we have a different definition.”

Griggs added: “The days of Terry Butcher soldiering on with a bloody bandage are gone. We cannot continue with a ‘patch them up, get them back out there’ approach to head injuries. Players must be protected.

“There needs to be greater transparency with these incidents. Silence from the Premier League is not helping. Instead, it is just confusing matters and undermining all efforts to lead an evolution of attitude towards head injuries at the grassroots level. Enough is enough.”

Koch was left covered in blood after clashing with McTominay in the 12th minute but returned to the pitch with his head bandaged before going down again and eventually being withdrawn in the 31st minute.

Football Association guidelines state that any player who sustains a suspected concussion should immediately be removed from the pitch, and extra permanent substitutions are allowed in such cases.

The PFA said in a statement on Twitter: “The injury to Leeds United’s Robin Koch demonstrates again that the current concussion protocols within football are failing to prioritise player safety.

“We see frequent incidents of players returning to play with a potential brain injury, only to be removed shortly afterwards once symptoms visibly worsen.”

The PFA added: “Put simply, the current rules set by IFAB (the International Football Association Board) are not working, and players are being put at risk.”

Leeds said in a statement that Koch had passed all of the on-field concussion screening tests that are currently part of the Premier League’s protocols.

They added: “The player was told if he developed any symptoms he should sit down on the field of play and would be substituted immediately, which is what Robin did in the 29th minute of the game.

“The medical staff at Leeds United have always been in favour of temporary substitutions for head injuries, as it would allow the staff more time to assess an injury and allow a period for symptoms to potentially develop.

“Robin will follow the concussion protocols before returning to play.”

German international Koch has thanked Leeds’ medical staff “for the good care” in a message posted on Twitter.

Koch said: “Thank you for your many messages. I wanted to support the team for longer yesterday, but unfortunately I couldn’t do it. Thanks to our medical staff for the good care. I feel much better today and will be back soon.”

The decision not to substitute Koch immediately drew criticism from several quarters.

Pundit Chris Sutton, whose father Mike – a former professional footballer – died with dementia in 2020, wrote on Twitter: “Football doesn’t care about its players. What needs to happen before the concussion procedure changes?”