Blades boss Micky Adams hopes Nick Montgomery, Richard Cresswell and Ched Evans will all be back in contention against Cardiff.
Midfielder Montgomery's wife recently gave birth to twins and strikers Cresswell and Evans also missed Saturday's home defeat to Middlesbrough due to respective groin/Achilles and knee injuries.
Adams will again be without midfielder Lee Williamson, who sits out the last game of a four-match ban.
Teenage midfielder Erik Tonne, signed from Strondheim in the January transfer window, made his first appearance as a substitute on Saturday and could feature again while striker Marcus Bent and winger Mark Yeates, who also stepped off the bench on Saturday, are pushing for recalls to the starting line-up.
The defeat to Middlesbrough saw them slip to the bottom of the table for the first time this season and they remain seven points from safety with six games left.
Jon Parkin will be monitored ahead by Cardiff as the promotion chasers aim to record a third successive victory.
The powerful striker, who has mostly played a substitute role since arriving at the club in January, missed Saturday's dramatic 3-1 win at Doncaster with a muscle strain.
However, Parkin did travel with boss Dave Jones' squad and, with the club staying in Yorkshire between the two games, will be assessed by medical staff prior to Tuesday's clash.
Jones must decide how best to utilise Jason Koumas after his match-winning two-goal cameo at the Keepmoat Stadium, although the on-loan Wigan winger is again likely to find himself on the bench ahead of Jay Emmanuel-Thomas.
Tom Heaton overcame a groin strain to start against Doncaster and should do so again unless he is feeling any ill-effects, with Stephen Bywater this time on standby to step in with fellow loan stopper Jason Brown having returned to Blackburn upon the completion of his month-long stay.
Michael Chopra continues to work on his quick comeback from a hamstring injury but will again miss out, as will centre-back Mark Hudson (knee) and goalkeeper David Marshall (elbow) with their long-term complaints.
