LEEDS insist they followed the Premier League’s concussion protocol with Robin Koch’s head injury in Sunday’s loss to Manchester United.

The Professional Footballers' Association and brain injury charity Headway have called again for the introduction of temporary substitutions after Koch was allowed to play on.

Leeds say they have always supported temporary substitutions for head injuries.

A club statement read: "Leeds United can confirm that following a clash of heads, Robin Koch passed all of the on-field concussion screening tests that are currently part of the Premier League protocols.

"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.

"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."

Koch was left covered in blood after a clash with Scott McTominay early in the match but returned to the pitch with his head bandaged before going down again and eventually being taken off.

The German international 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."

Meanwhile, Leeds have said they will issue lifetime bans to any supporters found to have thrown objects on to the pitch during their defeat to Manchester United.

Anthony Elanga was struck on the head by a coin as the away side celebrated going 3-2 ahead in Sunday's Premier League clash.

The Sweden international recovered to wrap up the points with a late fourth goal.

Now Leeds have acted and plan to come down hard on any fans shown to have thrown missiles.

"Leeds United are reviewing CCTV footage and we will do everything possible to find those supporters who are throwing objects onto the field of play," a Leeds spokesperson said.

"Any supporter caught throwing objects on to the pitch will be issued a lifetime ban from attending our fixtures."