Brain injury charity Headway claims concussion protocols were 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 Premier 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 (PFA) 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. The concussion protocols in the Premier League have been devised by IFAB and were approved by football’s lawmakers towards the end of 2020. 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 ...