Preston North End sealed the 27-year-old's services at the back end of last season on loan terms, and the Blades have turned to the manager-less outfit to secure a deal for the midfielder.
Williamson has been at a number of Football League clubs, including neighbours Rotherham United, but his dream to play in the top-flight, like every over professional, could become reality if he joins promotion contenders Sheffield United.
Half-a-million pounds is the cash amount Utd are prepared to cough up for the English-born-Jamaican. Everything seems to have been tied up, and conformation from the two clubs is all that's waiting for.