Boss Kevin Blackwell declared his frustration at the incident which forced striker Richard Cresswell temporarily out of the action during the 1-1 Steel City derby draw.
Cresswell appeared to be struck by Owls winger Jermaine Johnson's elbow in a tangle close to the touchline in the first half and left the field to have stitches inserted in a gashed forehead.
It was while the Blades were a man short that Wednesday broke the deadlock through Darren Potter's smart volley and Blackwell was angry the incident went unpunished.
Blackwell said: "You have got to question what happened to Richard Cresswell out there. It was a poor challenge and you should see the severity of the cut."
He added: "It was so jagged and there was so much blood that the medics couldn't get the stitches in. Unless Johnson has got studs in his arm, that was definitely an elbow.
"Cressy knows that he was elbowed. Going 1-0 down when you're down to 10 men is harsh - but life is full of injustices and you just have to carry on don't you?"
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