United's U18s slipped to a disappointing defeat at Coventry on Saturday.
Poor first-half finishing, combined with sloppy defending ultimately proved to be United's Achilles heel.
After a good start, which yielded many goalscoring opportunities for the Blades, the visitors fell behind on the half hour.
Cockerline, Coustrain, Wright and Cheeseman had all missed good chances, before a swift Sky Blues counter attack doubled their advantage.
Before half-time the hosts made it 3-0, although there was an element of fortune in the build-up.
The second-half started frantically and both sides had good chances. For the Blades, Cheeseman and Wright had chances to convert from a corner.
In the 80th minute a misplaced back pass allowed City to make it four, before WRIGHT netted a consolation for the Blades, from a Kedman cross.
Professional Development Phase Lead Coach, Travis Binnion, commented afterwards: "It seems silly because in truth we probably had enough chances to win the game.
"But you cannot concede four goals in a game and expect to win. Coventry fully deserved their victory as they showed more conviction and composure at both ends."
Blades: Owen, Paling, Ptak, Reed, Scarisbrick, Cheeseman, Wright, Lewin (Kedman 54), Cockerline (Slew 79), Heh (Fixter 71), Coustrain.