Midfielder Riise, who has made three appearances for the Blades since arriving on loan from Fulham, sustained a hamstring strain in the midweek defeat at Scunthorpe and is doubtful. Mark Yeates will step back in should he fail to make it.
Sam Vokes remains doubtful with a similar problem. The Wolves striker has made just one appearance for the Blades since arriving from Wolves on the same day as Riise.
Another loanee, Aston Villa defender Shane Lowry, is supended following his red card at Scunthorpe, so Johnny Ertl is likely to be recalled to the back four.
Chris Morgan along with fellow defenders Andy Taylor and Ryan France, goalkeeper Richard Wright, striker Darius Henderson and midfielder Nick Montgomery all remain sidelined as manager Micky Adams chases his first win after 11 games in charge.