An angry Chris Sutton called Michael Owen a 'caveman' live on BT Sport duty in a discussion involving concussion checks in football after an incident in Benfica's clash with Ajax.
Ajax defender Lisandro Martinez clashed heads with opponent Nicolas Otamendi in the first-half of the Champions League match and appeared to be affected by the blow, but carried the 24-year-old carried on playing and finished the 90-minute game.
Days after Leeds defender Robin Koch was forced off after being told to play on with concussion against Manchester United on Sunday, Sutton argued that players need to be properly assessed in a dressing room by an independent doctor before they can carry on.