The Red Devils earned a 3-1 win over Brighton & Hove Albion last time out as their positive form in other competitions begins to translate into their league showings.
However, they face a tough test against the Blades, who have defied expectations to go fifth in the league table, producing some impressive showings in the process.
Here, Sports Mole looks at how the Red Devils could line up for Sunday's showdown.
Out: Eric Bailly (knee), Scott McTominay (ankle), Marcos Rojo (muscle), Paul Pogba (ankle), Timothy Fosu-Mensah (knee)
Doubtful: Axel Tuanzebe (groin), Nemanja Matic (unknown), Luke Shaw (thigh), Diogo Dalot (groin)
Despite the raft of injuries United manager Ole Gunnar Solskjaer has to deal with, it is not likely that the Norwegian will be forced into many changes from the win over Brighton before the international break.
David de Gea will continue in goal, with the first-choice partnership of Harry Maguire and Victor Lindelof ahead of him. The injury to Rojo leaves only Phil Jones as cover for the starting pair, making it unlikely that Solskjaer would field all three of his fit senior central defenders at once to match the Blades' formation.
The only major change will come in midfield, with McTominay joining Pogba on the sidelines with an injury and Matic not yet match-fit. Assuming Solskjaer does not rush the Serbian back, youngster James Garner could be handed a rare opportunity in the Premier League alongside Fred in a double-pivot.
Ahead of them, Andreas Pereira will expect to keep his spot ahead of Juan Mata and Jesse Lingard after his goal against the Seagulls, while Marcus Rashford, Anthony Martial and Daniel James is clearly Solskjaer's preferred front three and should start together again.