David Weir rates Febian Brandy as 'touch and go' for Saturday's clash with MK Dons at Bramall Lane.
The exciting forward limped out of the action early in the second-half at Bradford on Saturday and has worked with the physios throughout the week to date, rather than joining in with the full group.
Speaking at his pre-match press conference at Shirecliffe, Weir said: "Febian hasn't trained this week and because it is a hamstring problem you have to be very careful.
"The main issue is pace is such a vital part of Febian's game and hamstrings are a dangerous muscle to push in that respect.
"It is something we need to keep an eye on; but he is certainly touch and go for the weekend."