Williams, who joined the Blades from the Royals on a free transfer in January 2012, missed last week's draw at Notts County, but could be back in contention, while Darryl Westlake should continue if he fails to make it.
Manager Danny Wilson has no new injury or suspension worries, but is currently short on defenders as Neill Collins (fractured cheekbone), Matt Hill (broken jaw) and long-term absentee Lecsinel Jean-Francois (knee) are all sidelined.
Striker Shaun Miller is out for the rest of the season due to knee ligament damage and although goalkeeper Mark Howard has returned to training following a long-term thigh injury, he is not ready for first-team action so George Long will continue.
- Sports & Recreation
- Neill Collins