James Beattie has accused Angel Rangel of play acting to get Darius Henderson sent off last weekend
The Swansea City defender was involved in the incident that left the Blades down to ten men for most of the second half in the 1-1 draw at the Liberty Stadium last weekend.
Referee Andre Marriner adjudged Henderson to have elbowed Rangel and immediately showed the red card to the player who cost them £2m from Watford in the summer.
But Beattie - the Bramall Lane record signing - said "Fair enoughm Darius slightly caught him, but the Spanish lad reacted like he had been shot.
"He went down in a heap then jumped up to his feet and carried on playing as though nothing has happened straight after Hendo's sending off.
"A more honest player would never have behaved like that. He would have told the ref that Darius barely touched him."