Chris Wilder has revealed he has a couple of fitness doubts, ahead of Saturday's clash with Wigan Athletic at Bramall Lane.
Speaking at his pre-match press conference on Thursday, the manager said there were a few bumps and bruises following Tuesday's clash against Stoke City.
He remarked: "We've got a couple of injuries that we'll have to assess in the next couple of days, but we'll give the players as long as possible.
"As you can imagine, I'm not going to give you any names or clues, but whoever comes into the needs to play well to replace those that might be unavailable.
"I'm delighted to have dilemmas, I'd take having dilemmas all day long, the more the merrier, the better that is for us and me."
Wilder added: "What I do know is the work those who aren't playing are doing is outstanding, we keep a close eye on those guys because they have to be ready to set up when required.
"We always ask how they've been if they've worked away from the main group and consistently the word that is used is outstanding.
"The effort they are putting in away from the bright lights and the games, that can sometimes be tough if they aren't in the starting 11 or even in the matchday 18.
"It's obviously a fantastic job and a great career, but sometimes it's difficult away from the glamour that comes with being a professional football, but they are working as hard as possible to ensure they're ready."