It can now be confirmed that the Blades completed the loan transfer of Marvin Johnson on time.
After negotiations with Middlesbrough, United officials beat off attentions from other clubs submitted the paperwork ahead of the 5pm EFL loan deadline.
Johnson is United's second capture on deadline day and eighth in total of the summer transfer window.
Blades chief Chris Wilder commented: "Marvin gives us plenty of options, quick, left-footed and can play in a number of positions. We've tracked him for a while for good reason, we are delighted that we've finally got his signature."
Birmingham-born Johnson began his career in non-league with Solihull Moors, before representing Romulus, Kidderminster Harriers and Hednesford Town.
In February 2015, having had numerous trials with EFL clubs, Johnson joined Motherwell on transfer deadline day, penning a three-year extension at the end of the 2015/16 campaign. But in August 2016, again on deadline day, the 27-year-old moved to Oxford United, with the U's paying a fee believed to be a club record £650,000.
The winger impressed at the Kassam Stadium and Middlesbrough beat off competition from Hull City and Birmingham City to secure his services on deadline day in August 2017, with Johnson penning a three-year deal at the Riverside.
Last season, Johnson made 22 appearances in all competitions for Boro. He was on the bench when United visited the north-east earlier this month and he featured and scored in their Carabao Cup success over Rochdale in midweek.