Leeds United defender Robin Koch was forced off with a head injury yesterday afternoon.
The German international was bloodied during a coming together with Manchester United's Scott McTominay and required medical assistance on the Elland Road pitch.
After a stoppage of several minutes, Koch replaced his shirt and shorts, before returning to the field of play.
The Professional Footballers' Association has criticised Leeds' following of the concussion protocols by allowing the defender to return to the pitch without more extensive assessment by club doctors.
"The injury to Leeds United’s Robin Koch demonstrates again that the current concussion protocols within football are failing to prioritise player safety," the union's official account tweeted.
"The ‘if in doubt, sit them out’ protocol is not being applied consistently within the pressurised environment of elite competitive football."
Leeds United have issued a response to these comments, stating: "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 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," it finished.
Koch has reassured fans on social media with the following statement: "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."
