O'Grady, 28 was recently on the verge of completing a move to Championship side Charlton Athletic for a reported £500k but the deal fell through. However the Sheffield Telegraph has revealed that the Blades are now interested in the former Rotherham United striker who scored 15 goals last season for the Tykes despite suffering relegation.
A statement was read out last week which suggested that United would find it "impossible" to sign the striker, however it is understood that exploratory talks have taken place and despite signing Marc McNulty and Jamal Campbell-Ryce (as well as rewarding Chris Porter with a new contract) it appears that O'Grady is still on Nigel Clough's hit list.
Should O'Grady sign for the Blades when the S2 club would become his twelth different club since 2003.