United's second string surrendered a lead to lose 2-1 against Derby County at Belper Town's Christchurch Meadow in Wednesday night's totesport.com league clash.
The Blades, who included, Rob Kozluk, Matt Lowton, Mark Yeates and Daniel Bogdanovic, took the lead on the half hour mark, when the latter finished excellently, but goals from Callum Ball and Conor Doyle saw the Rams take the spoils.
United started brightly and trialist Francis Laurent drew a good save from Deeney, before Chapell and Lowton wasted good opportunities following good work by Bogdanovic.
The home side responded well and created a chance of their own, but Martin fizzed his low drive wide after Mendy had won the ball in midfield and sent him clear.
United had shown plenty of positive signs in the opening exchanges and they were rewarded in the 30th minute, BOGDANOVIC showed neat control to create an opening in the box before curling a precise effort into the top corner past the helpless Deeney.
County were quickly back on level terms though when BELL glanced home a header from a Jones cross, which evaded Aksalu's best efforts to keep it out.
Early in the second-half the hosts got what proved to be the winner, when DOYLE rounded off a move with a composed finish from 12 yards out, although he was given too much time as the defence backed off.
Chances were at a premium from then on, although Pomares almost snatched a point late on, after Maguire had been deployed as an emergency striker, but Galinski cleared off the line when the ball seemed destined to hit the back of the net.
Coach Mark Smith was disappointed that United hadn't built on last week's impressive display against Nottingham Forest and bemoaned the way both goals were conceded:
"It was a decent game, but it was far too open, especially in the first-half where it was like a game of basketball, although overall we probably did enough to get a draw.
"There were some good pockets of play but in other areas, mainly out of possession, we let ourselves down and both goals could have been avoided on another night, so it really was an opportunity missed."
Blades: Aksalu, Kozluk, Roe, James, Lowton, Pomares, Laurent (Adams 65), Sykes, Bogdanovic (Maguire 70), Yeates (Hinchcliffe H/T), Chapell.
Unused: Long, Lammy.
