Summer signing James Wallace is a major doubt for Sheffield United's home game against Bristol City.
Midfielder Wallace, who penned a two-year deal in June following the expiry of his contract at Tranmere, is struggling to make the opening game.
Boss Nigel Clough said: "If he misses out we're hoping he can feature against Mansfield on Tuesday in the (Capital One) Cup but he's got a niggling groin problem from the back-end of last season."
Latest recruit Michael Higdon, who joined from Dutch side NEC Nijmegen earlier this week, is unlikely to be included as he builds up his match fitness but Clough expects his other summer signings - Chris Basham, Andy Butler, Jamal Campbell-Ryce, Ben Davies, Harrison McGahey and Marc McNulty - to be in contention.
Bristol City have no fresh injury worries as they look to cause an upset at Bramall Lane.
Defender Karleigh Osborne is manager Steve Cotterill's only question mark ahead of kick-off but the former Brentford centre-back has trained with his team-mates after a shin injury and he is expected to make the journey north.
Cotterill has made six summer signings and they are all expected to be in the matchday squad. Defenders Mark Little and Luke Ayling and midfielders Wade Elliott, Korey Smith and Luke Freeman are all fit and available to join experienced striker Aaron Wilbraham in the 18.
City have not won at the home of the Blades since November 1957 - a run of 18 matches.