Blades boss Danny Wilson raged at referee Steven Rushton after two red cards for his side during the 1-1 draw at Scunthorpe.
However, Wilson was full of praise for his nine-man team who fought back to draw with an 83rd-minute equaliser from centre-back Neill Collins.
That followed the dismissals of skipper Michael Doyle after just 15 minutes and midfielder Ryan Flynn in the 72nd minute.
"We have been asked not to criticise referees but it it difficult to accept that when you get a performance like we have seen here," fumed Wilson. "It was an absolutely terrible game from this referee's perspective.
"First he has sent Michael off for an alleged stamp. But he got nowhere near their player, he was a foot away from making contact. And then in the second half the referee has sent off Ryan. It was a situation where both players were going for the ball hell for leather. It was a booking at best, but the sending off was ridiculous.
"Of course we will be appealing against each red card and I just hope that the referee realises the mistakes he has made. If he does that, then he will come out of it a better man. What he has done is spoil what could have been a very good match."
