United's recruitment drive continues to gather pace, with Chris Wilder adding a sought-after midfielder to the ranks.
The Blades have secured the services of John Fleck, formerly of Coventry City, on a free transfer, with the left-footed player penning a three-year deal at S2 after turning down options to play at Championship level.
Fleck, who has spent four seasons with the Sky Blues, made 43 appearances for City last season, scoring four goals.
The 24-year-old started his career at Rangers and made over 50 outings, prior to cutting his teeth south of the border at Blackpool during the second-half of the 2011-12 campaign.
In the summer of 2012, following his release from Ibrox, the former Scotland U21 international joined Coventry and has become one of the most consistent ball-playing midfielders in the third tier.
On the signing of the Scotsman, boss Chris Wilder commented: "John is an outstanding midfield player in League One and we believe he can play at a higher level.
"He is another to have contract options and we are delighted to get him to Bramall Lane as he is athletic, hungry, a great age and fits the structure of the players we want to represent the club."
Fleck becomes United's fifth signing of the summer and second inside a few hours, following the arrival of defender Jack O'Connell. The signatures of James Wilson, Chris Hussey and Mark Duffy have also been secured.