Leicester boss Steve Cooper criticised the standard of refereeing and believes it is "behind the curve" in the Premier League.
The Foxes manager was unhappy with several decisions by official David Coote in their 2-1 defeat to Aston Villa on Saturday.
Goals from Amadou Onana and Jhon Duran gave Villa victory, with Facundo Buonanotte pulling one back for the hosts.
Cooper was booked for protesting when Leicester were not awarded a penalty after Jamie Vardy went down under a challenge by Youri Tielemans.
There were several other decisions the Foxes were unhappy with, including the decision to penalise Oliver Skipp for bringing down Ollie Watkins for the free-kick which led to Villa's opener.