Murphy, 24 is set to leave the Crown Ground on a free transfer following the end of his contract and also turning down a new deal from Lancashire club Accrington Stanley who are managed by former Blades striker James Beattie.
According to Sky Sports News the Blades, as well as Milton Keynes Dons, Oldham Athletic, Preston North End and Tranmere Rovers are all vying for his services for the defender who scored nine times in 47 games this season. The Blades will be looking for new recruits either as back-up.