Sheffield United pair Jose Baxter and Stefan Scougall are both doubtful for the home game against Brentford.
Striker Baxter took a kick on the hip during Saturday's defeat at Swindon and midfielder Scougall was also forced off due to a hamstring problem.
Harry Maguire sits out the second game of a two-match ban and fellow defenders Matt Hill (hamstring) and Bob Harris (thigh) remain sidelined.
The Blades have won only one of their last four league games since their nine-match winning run was halted in a goalless draw at Preston earlier this month.
Brentford expect Tony Craig and George Saville to be fit for the trip to Sheffield United.
Defender Craig was left on the bench for Saturday's goalless draw at Oldham as he was struggling with illness, while on-loan Chelsea midfielder Saville failed to shake off a knock in time.
But boss Mark Warburton is confident the duo will be in contention to face the Blades as promotion-chasing Brentford look for a first win in three games.
Winger Sam Saunders is still recovering from a knee operation but hopes to be back in a couple of weeks.