United's U23s came up short against a strong Aston Villa side in the Premier League Cup on Thursday evening.
Second half goals from Harvey Knibbs, Jack Clarke, and Jordan Cox condemned United to defeat at Hednesford Town.
Chances were scarce in the opening 45 minutes, but the Blades were edging it trying to force a mistake out of the Villa defenders to spark an opportunity.
McKirdy seemed to be clean through to give the hosts the lead going into the break but a great last ditched challenge from trialist Scott saw the danger averted.
The Blades had the ball in the net as Smith turned home at the far post right on half time but the offside flag was raised.
However five after the interval the home side would have the advantage as a break down the left hand side led to a low ball into KNIBBS who finished convincingly to break the deadlock.
Shortly after Knibbs somehow squandered a chance to put Villa two goals to the good as he found himself in front of an open goal from close range but he couldn't find the net.
United had chances to equalise but failed to test the goalkeeper as efforts Smith and Hallam narrowly evaded the goal.
As the final quarter of an hour approached United conceded a second as CLARKE went on a solo run through the Blades backline and then neatly chipped Eastwood to double the lead.
Just four minutes later Villa sealed the points as the Blades were searching for a way back into the game as COX struck fiercely to put the hosts out of sight at Keys Park.
Blades: Eastwood, Portman (Wright 58), Norrington-Davies, Scott, Graham, Cantrill, Gilmour, Slater, Smith, Hallam, Doherty.
Unused: Dewhurst, Hawkes, Parkhouse, Cutts.