The Tykes edged out Wigan Athletic on penalties to avoid an immediate elimination, while their second-tier foes emerged victorious from a six-goal thriller with Wrexham.
Match preview
With another League One playoff push at the forefront of Barnsley's minds, EFL Cup stardom will be low down the list of the Tykes' priorities for 2024-25, but Tuesday's hosts have already bettered their run from 2023-24 by virtue of holding their nerve from 12 yards.
Twelve months ago, Barnsley's penalty prowess eluded them in a first-round exit to Tranmere Rovers, but Darrell Clarke's side fought back to hold Wigan to a 1-1 draw in this year's first round before on-loan Chelsea man Gabriel Slonina stopped Thelo Aasgaard and Josh Stones from the spot.
A first third-round appearance since 2020-21 - where Chelsea hit them for six - is therefore within touching distance for Barnsley, but their overall start to the 2024-25 campaign has been nothing to write home about, with four points from their first nine on offer in League One.
A 2-1 loss to Mansfield Town and victory over Lincoln City by the same scoreline preceded a 2-2 stalemate with Northampton Town on Saturday, where Clarke's men were two goals to the good heading into the final 20 minutes only to catastrophically throw their lead away.
The Tykes also started their EFL Trophy campaign on the wrong foot with a 3-2 home defeat to Manchester United's Under-21s, but the neutrals can at least expect entertainment at Oakwell, as each of Barnsley's last 14 competitive matches has seen both teams score.
Entertainment was not in short supply at Bramall Lane in the first round of the EFL Cup either, as Sheffield United subjected more knockout misery on Wrexham, whom they memorably left heartbroken in the fourth round of the 2022-23 FA Cup.
Despite conceding first on August 13, Chris Wilder's men breached the Wrexham backline four times to ensure that a first-round giant killing would not be on the cards, and they have maintained their unbeaten start to 2024-25 since.
However, that 4-2 beating of the Dragons remains their most recent success in any competition, as the Blades have since been forced to accept Championship draws with Queens Park Rangers (2-2) and Norwich City (1-1) to leave them with three points from a possible nine; they were deducted two at the start of the term for financial indiscretions.
As a result, the Blades are already marooned in mid-table and have early ground to make up in the promotion fight, while their EFL Cup run in 2023-24 coincidentally ended in round two at the hands of lower-league opposition in the shape of Lincoln City.
Sheffield United did the double over Barnsley during their most recent showdowns in the 2021-22 Championship campaign, though, and the Tykes' last triumph in this fixture came back in 2018, when Oli McBurnie was coincidentally among the scorers against his future employers.
Barnsley EFL Cup form:
W
Barnsley form (all competitions):
Sheffield United EFL Cup form:
W
Sheffield United form (all competitions):
Team News
Even though Barnsley right-back Corey O'Keeffe was sent off in the recent EFL Trophy loss to Man United, his suspension only applies to that competition, meaning that he is at Clarke's disposal for the visit of Sheffield United.
Striker Max Watters also overcame a hamstring concern to play 66 minutes of the draw with Northampton, where left-back Georgie Gent was taken off at the break, although that appeared to be a tactical tweak.
Clarke did not hold back at full time at the weekend, accusing his side of having a soft underbelly, so alterations in the middle with Jon Russell and Vimal Yoganathan would not be a total surprise.
Regarding Sheffield United's availability, full-back duo Femi Seriki and Jamie Shackleton are both on the mend from respective knee injuries, so Chelsea-owned Alfie Gilchrist should start on the right as he faces up to fellow Blue Slonina.
However, none of Wilder's troops picked up any fresh issues in the draw with Norwich, where Michael Cooper made his Blades debut in goal, but Ivo Grbic may now return for cup duties.
Two scorers from the Wrexham success - Anis Slimane and Louie Marsh - should be among the names considered for starts by Wilder, who could also take a punt on Rhian Brewster up top again.
Barnsley possible starting lineup:
Slonina; Earl, Pines, Roberts; Lofthouse, Russell, Craig, Hourihane, Gent; Cosgrove, Watters
Sheffield United possible starting lineup:
Grbic; Gilchrist, Souttar, Trusty, McCallum; Rak-Sakyi, Peck, Coulibaly, Slimane; Marsh; Brewster
We say: Barnsley 1-2 Sheffield United
Goals at both ends of the pitch are almost a guarantee whenever Barnsley are in action, and Tuesday's tie should be no different, especially after their calamitous defensive capitulation at the weekend.