The Blades currently sit second with a 10-point lead and a game in hand over their visitors, after both triumphed in their last league outing at the weekend.
Match preview
Sheffield United come into Wednesday's crucial match in a strong position in the fight for automatic promotion to the Premier League this season, having established themselves in the top two with a healthy 10-point lead over the chasing pack.
That position has been strengthened by the Blades' eye-catching run of form following the World Cup break in December, having not lost any of their nine league matches since while only playing out two draws.
The most recent of those came away at Rotherham United at the beginning of February, as neither side managed to break the deadlock in a South Yorkshire Derby, and after eventually getting past Wrexham in their FA Cup fourth-round replay at Bramall Lane last Tuesday, courtesy of injury-time goals from Billy Sharp and Sander Berge in a 3-1 victory, Paul Heckingbottom's side set out to make a return to winning ways in the league when they hosted Swansea City on Saturday.
Berge was again on the scoresheet to put his side ahead in the 21st minute of that game, and after Jack Robinson doubled their lead on the stroke of half time, Oli McBurnie capped off a dominant display with a goal late on to seal a 3-0 triumph.
Such a result saw the Blades move onto 61 points from their 30 outings, having won 18 of those while only conceding 24 goals - making their defensive record the tightest in the division at this stage - and now with a 10-point lead over their third-placed opponents and with a game in hand, they will know that a victory on Wednesday will be another huge step to securing a top-two finish and a return to the top flight.
They take on a Middlesbrough side who have gained major ground in the promotion race since Michael Carrick's appointment as manager in October, having now won 10 of their last 12 league matches to climb from the fight at the bottom end of the division up to third spot.
In that run, Boro have netted 26 goals to take their tally to 50 for the season in the second tier, with that attacking record now only topped by runaway leaders Burnley and Wednesday's hosts.
After a run of four straight victories was halted by a disappointing 2-0 derby defeat to Sunderland, the Riverside outfit have bounced back in impressive fashion and now head to Bramall Lane on the back of three more wins on the bounce, having firstly beaten Watford and Blackpool 2-0 and 3-0 respectively on home turf.
Carrick's men would then travel to take on Cardiff City on Saturday, and after Marcus Forss's opener was cancelled out in the 25th minute, Cameron Archer would restore Boro's lead before Riley McGree added a third in the dying minutes to wrap up their 15th league win of the campaign.
Now facing one of their toughest games of the season, and with any real hopes of automatic promotion likely riding on dishing out a defeat to the Blades, Carrick's men will aim to make it four three-point hauls on the spin to start narrowing the gap to the top two while also further strengthening their position in the playoff spots.
Sheffield United Championship form:
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Middlesbrough Championship form:
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Team News
Sheffield United could come into Wednesday's contest with an unchanged starting XI from their victory over Swansea, although Oli McBurnie will be pushing to come back in up front from the outset after hitting his 10th league goal of the season off the bench.
He will hope to join Iliman Ndiaye, who has also starred this term with 10 goals and seven assists in the Championship, while Sander Berge, James McAtee and Oliver Norwood should all keep their places in midfield in the continued absence of John Fleck and Tommy Doyle.
Heckingbottom is also unlikely to make any changes to his defence, with Max Lowe and Jayden Bogle bound to again operate in wing-back roles with Enda Stevens, Rhys Norrington-Davies and George Baldock remaining sidelined, while Anel Ahmedhodzic and Jack Robinson will continue to join John Egan in a back three.
Middlesbrough could also come into the game with an unchanged starting XI from their victory at the weekend, with Marcus Forss and January arrival Cameron Archer both expected to keep their places in the front line after getting on the scoresheet, while Chuba Akpom is bound to start again, with the 27-year-old four goals clear at the top of the league's scoring charts with 16 in 24 Championship appearances.
Midfielder Dan Barlaser will be hoping to earn a first start for the club after joining from Rotherham United in the January transfer window, although Carrick has stuck with the pairing of Hayden Hackney and Jonny Howson in the engine room recently with Riley McGree offering further attacking support.
Dael Fry and Isaiah Jones are also vying to come in from the outset in defence, but we should see an unchanged back four featuring Tommy Smith, Paddy McNair, Darragh Lenihan and Ryan Giles with centre-back Matt Clarke remaining confined to the treatment room.
Sheffield United possible starting lineup:
Foderingham; Ahmedhodzic, Egan, Robinson; Bogle, Berge, Norwood, McAtee, Lowe; McBurnie, Ndiaye
Middlesbrough possible starting lineup:
Steffen; Smith, McNair, Lenihan, Giles; Hackney, Howson; McGree, Forss; Archer, Akpom