Matthijs de Ligt was left with a bloodied head following a clash with Kevin Schade towards the end of the first half in Saturday's game between Manchester United and Brentford.
United defender De Ligt's head collided with Brentford winger Schade's knee while the game was still tied at 0-0.
But after De Ligt had been ordered off the field to receive treatment for his messy wound, Brentford scored the opening goal as Ethan Pinnock headed home from a Mikkel Damsgaard corner kick.
Red Devils manager Erik ten Hag was furious after his side had to defend the corner with just 10 men and he directed his anger at the officials, resulting in a yellow card.