United's U18s saw their five-game unbeaten run come to an end, after succumbing 3-0 to a more experienced Nottingham Forest outfit on Saturday.
The hosts showed more maturity in difficult conditions and the result was never really in doubt, despite the Blades' best efforts.
Forest started brightly and took the lead in the 15th minute after United's defence failed to clear a loose ball.
The visitors responded well to going a goal down with Roe sending a free-kick just over, before Slew beat two defenders only to see his cross-shot evade the onrushing Gregory.
After the break United appeared to be matching their opponents up tactically and. despite not creating many clear cut chances, Slew and Chappell were looking dangerous when running with the ball.
The introduction of Foster caused Forest's backline problems and Roe again come within a whisker off drawing United level.
Two goals in five minutes effectively ended the game as a contest. The first came direct from a goal kick, before Andrew misjudged a high ball in the swirling wind.
The goalkeeper went some way to making amends moments later to deny the home side a fourth.
Coach Kevin Fogg was disappointed with the result, but was keen to emphasise the importance of learning from this type of situation:
"Forest had to much for us and handled the conditions a lot better but, in saying that, we have got to develop the lads and the injuries and illnesses in the squad gave some of the youngsters the chance to impress.
"What this performance shows though is that we need to improve to reach the high standard that is consistently on view in this league."
Blades: Andrew, O'Kane, Roe, Wilkinson, Maguire, Darlow, Lammy (Ahmadi 63), Murray, Slew (Foster 63), Gregory (Pennycooke-Morgan 80), Chappell.
Unused: Pomares.