The Blades have extended the loan deal of Kieron Freeman until the end of the season.
The 22-year-old from Derby County had originally signed a one-month loan deal but now the paperwork has been completed to enable him to stay at Bramall Lane until the end of the campaign.
Freeman has started the last six games, more recently filling in as a left-back.
Boss Nigel Clough commented: "He gives us versatility, which was always the plan with Kieron, it has been very helpful having him to play at left-back in recent weeks. I’m delighted that all has been agreed and the paperwork tidied up to enable him to stay with us."