Professional Game Match Officials Limited (PGMOL) is to conduct an investigation into referee Mick Russell's failure to send off Sheffield Wednesday's Jeremy Helan in Saturday's 0-0 draw with Huddersfield.
Helan was shown a first yellow card by Russell for diving in the ninth minute and was then given a second for a 26th-minute foul on Adam Hammill.
However, Russell, who has since admitted making an error, attributed the first booking to Helan's team-mate Michail Antonio. When he went to book Helan for the second offence he had no note of the first booking by the player's name, and so did not send him off.