Here's a look at the last fives matches between the two clubs, ahead of tonight’s big match. Click and scroll through the gallery to see how the Blades have fared in their recent clashes...
1. Sheffield United 3-0 Sunderland
December 2017: A Boxing Day belter here for Blades fans, who saw their side tear apart the Black Cats in comprehensive fashion. Richard Stearman, George Baldock and John Lundstram bagged the goals, in a game that saw United end a seven-game streak without a win. (Photo credit: Simon Bellis/Sportimage) Photo: Simon Bellis
2. Sunderland 1-2 Sheffield United
September 2017: It was a debut to remember for Clayton Donaldson, who scored two clinical goals to give his side the win. Chris Wilder was delighted, and claimed he'd try to sign the player on eight previous occasions. (Photo by Stephen Pond/Getty Images) Photo: Stephen Pond
3. Sunderland 1-0 Sheffield United
January 2005: Stepping back in time 12 years, the Black Cats edged this one thanks to Marcus Stewart's late volley. Neil Warnock was typically bullish in his press conference, claiming Sunderland wouldn't fancy playing his side again in the play-offs. (Photo by Matthew Lewis/Getty Images) Photo: Matthew Lewis
4. Sheffield United 1-0 Sunderland
September 2004: Despite a fantastic appearance from goalkeeping cult hero Mart Poom, the United eventually managed to find a way to get past the Black Cats, as Paul Shaw took advantage of a defensive mix up to slot home the winner. (Photo by Laurence Griffiths/Getty Images) Photo: Laurence Griffiths