Despite a much improved performance, United's youngsters slipped to defeat against Barnsley at Oakwell Academy on Saturday.
United created the better chances throughout the game and dominated for long periods, but the home side were clinical in front of goal and scored in each half to take the spoils.
It was the visitors that were quickly on the front foot, Gordon headed over after good play between Cockerline and Brown, before Slew missed his kick from point blank range with the goal at his mercy.
United continued to press forward and appeals for a penalty waved away in the 22nd minute, when Slew got the wrong side of his marker and appealed to be bundled over as he prepared to get his shot away.
At the other end, the referee didn't hesitate in pointing to spot to allow the Tykes the chance to open the scoring which they duly accepted moments later, Gordon and Hinchliffe missed tackles in the build-up and the onrushing striker managed to force his way between Evans and Adebowale before the referee spotted a coming together in the box.
United reacted well though and Gordon raced clear on the counter attack after a lovely through ball from Ramsey, but unfortunately his effort was off target.
On the stroke of half-time, poor decision making in the final third from Cockerline saw another chance spurned as he opted to go alone despite having Slew and Ramsey in support in a three on two break.
The Blades picked up the pace quickly after the interval too, a good passing move created an opening for Gordon, who really should have scored from inside the penalty area and the Northern Irish youth international was soon in the thick of the action again, this time heading over from six
In the 68th minute, with United dominating proceedings Cockerline struck the crossbar after Barnsley failed to clear a corner and despite his best efforts substitute Fixter couldn't force the ball home in the resulting melee.
Skipper Kelly was the next to try his luck in the 75th minute, but after a marauding run he decided to shoot when Slew was well position in the penalty area, similar to Cockerline's chance before the break.
United's failings in front of good proved costly with just under ten minutes remaining, as Barnsley doubled their advantage to make the game safe with a swift counter attack and the home side should have made it three in the final moments but missed a free header at the back post with Ramsdale stranded.
Coach Travis Binnion was happier with the performance of his players, but was left ruing lapses in concentration defensively, he remarked:
"It was a much improved performance and we created enough chances to win the game comfortably.
"But we switched off at crucial times when under a bit of pressure and Barnsley have taken their chances, whereas we have been wasteful with ours.
"Despite that there were a number of positives to take from the game and into training over the next week."
Blades: Ramsdale, Brown, Kelly, Evans, Adebowale, Gordon, Hinchliffe, Brooks (Hutchinson 71), Ramsey (Fixter 59), Cockerline, Slew.
Unused: Perryman, Gilmour.