Chris Wilder has acted quickly in reshaping his squad, with the additions of two players, subject to Football Association and Football League clearance.
The Blades have signed a pre-contract agreement with experienced winger Mark Duffy, who will officially join the Club on a free transfer on the 1st July, following his release by Birmingham City, whilst Bury's Chris Hussey will join United for an undisclosed nominal fee, having impressed in making 50 appearances in all competitions for the Shakers last term.
United have fought off competition from the Championship and a number of rival clubs in League One to secure the signature of Duffy, who was instrumental in helping Burton Albion win promotion to the second tier whilst on-loan at the Pirelli Stadium during the 2015/16 campaign.
The 30-year-old was a near ever present for the Brewers, making 45 league appearances in total, scoring eight goals and contributing a number of assists in the process. His consistent form also saw him recently named in the PFA League One Team of the Year.
The Liverpool born operator has penned a two-year contract at Bramall Lane, much to the delight of Wilder, who remarked: "In our opinion, Mark was the best player in this division last season and we are delighted to have captured his services. Importantly he knows what it takes to get out of League One, which is crucial.
"He comes here for all the right reasons, he has come here because after listening to us he believes in what we are trying to do, Mark could have moved elsewhere for a significantly better contract.
"Mark scored and created a good number of goals for Burton, he deservedly was named in the divisional team of the year and is a player we believe can make an impact immediately and also make the step up to the division above."
Meanwhile, 27-year-old Hussey will arrive in South Yorkshire on a two-year deal having caught the eye of United's new boss and his assistant Alan Knill for David Flitcroft's side last season.
A strong and energetic left-back, who can also operate in a more advance role, also lists AFC Wimbledon, Coventry City and Burton amongst his former clubs, having begun his career at Woking.
Of the addition of the London born performer, manager Wilder added: "Chris was another really consistent player in this division last season and we are delighted to have brought him here.
"He offers us balance, versatility and a good knowledge of the league; in addition we believe he is capable of making the step up to the Championship.
"Chris is a good age and a player we have monitored and tracked for a number of years."