Shaun Miller and Ryan Flynn both picked up calf injuries in Tuesday's 3-3 draw with Crewe Alexandra, to leave Danny Wilson pondering an imminent dip into the loan market.
Hamstring injury victims Tony McMahon and Matt Hill also missed out for a second game running and Wilson says he is reluctant to rush either back too soon and risk them being sidelined for longer.
Wilson commented after the game: "Shaun again looked as bright as button, his movement is terrific. He had a bit a calf strain at the end but he looked sharp, got his goal and had a few other chances too.
"Ryan got a whack in the calf, he was on the end of several challenges in the first-half and unfortunately he was too sore to carry on.
"Neither Tony or Matty were considered, they will be in for more treatment on Wednesday and both will be assessed ahead of the weekend."
On the recent addition of Danny Coyne to the squad and possible reinforcements arriving before Thursday's loan deadline, the Blades boss concluded:
"We couldn't keep gambling and Danny's experience could be paramount. We needed a goalkeeper, not just for matches but also in training - goalkeepers need to train together and it would have been difficult with just George (Long).
"We will have to wait and see if anything happens before the loan deadline, we are trying our best because we need some experience, we are operating with a shoestring squad at the moment.
"I am always optimistic of getting players in, but let's see what progresses in the next 24 hours or so."