Central defender Maguire (knee) and striker Porter (hamstring) were forced out of Sunday's FA Cup draw with Fulham and were due to have late fitness tests ahead of the postponed midweek fixture against Peterborough.
The Blades will be without skipper Michael Doyle, who starts a three-game ban following his straight red card against Fulham, so recent midfield signing Stefan Scougall could make his first start.
Defenders John Brayford (Cardiff) and Bob Harris (Blackpool) are hoping to make their first league appearances for the Blades following their respective debuts after joining the club on loan last week.
- Sports & Recreation
- Stefan Scougall
- Michael Doyle