By SABC Sport
14th February 2024
Wilder was incensed when one of referee Tony Harrington's assistants was consuming a sandwich when the Blades manager went to see him after the 3-2 defeat at Crystal Palace last month.
Wilder described it as a "complete lack of respect" and also called Harrington's performance "ridiculous" in an interview with BBC Radio Sheffield after the game.
He said: "It's yet again another ridiculous performance from the referee.
"Every 50/50 or tight decision goes against us and if that's what we're going to have to deal with between now and the end of the season, we're going to deal with it.
"But I'm not just going to go under the radar and not say anything. I've been to see the referee and I've told him that.
"One of his assistants was eating a sandwich at the time, which I thought was a complete lack of respect. Hopefully he enjoyed his sandwich while he was talking to a Premier League manager."
The Football Association has sanctioned the Blades boss with a charge of improper conduct.
It said in a statement: "Chris Wilder has been charged with a breach of FA Rule E3.1 in relation to media comments that followed Sheffield United's Premier League match against Crystal Palace on Tuesday 30 January.
"It's alleged that the manager's comments constitute improper conduct in that they imply bias and or/attack the integrity of the referee, or referees generally, and/or bring the game into disrepute.
"Chris Wilder has until Friday, 16 February, to provide his response."