Nyron Nosworthy could be fit to be part of Gary Speed's first game as Blades manager.
The loan defender has missed the start of the season with a groin problem but is nearing a return and could be considered for Sunday's 1.15pm kick-off at Middlesbrough.
Boss Speed confirmed: "Nyron has trained this week, he's not 100 per cent yet but we will see how he does on Saturday before making a decision."
New signing Stephen Jordan is edging closer to a return but won't be considered for the trip to the Riverside, whilst Darius Henderson, Lee Williamson and Ryan France remain long term absentees.
Young defender Matt Lowton will again miss out. Sunday is the final match of this three-game ban following the red card at Cardiff City on the opening day of the season.
Former Blade Matt Kilgallon could make his Middlesbrough debut in the npower Championship clash.
He joined Boro on a season-long loan from Sunderland this week and has indicated that he could be used in a left-back role.
Riverside skipper Gary O'Neil is a doubt with a knee problem and illness, whilst Seb Hines, Kevin Thomson, Willo Flood, Jonathan Franks and Rhys Williams are all out.
Boro also lost goalkeeper Brad Jones in the week when he was sold to Liverpool.