Leeds United's response to the head injury suffered by defender Robin Koch in Sunday's 4-2 Premier League defeat by Manchester United must not be dramatised, manager Marcelo Bielsa said on Tuesday. Koch was left bloodied after a clash of heads with Scott McTominay early in the match and continued to play on with heavy bandaging before being substituted in the 31st minute. The Professional Footballers' Association said the existing concussion protocols failed to prioritise player safety while Brain injury charity Headway said it was "frustrated and confused" at football's response to the issue.