United's U23s slipped to a harsh home defeat against Hull City on Monday afternoon.
A brace from Keane Lewis-Porter and a goal from Billy Chadwick saw the Tigers to victory, but the scoreline didn't reflect the performance of the Blades youthful side, which also included two trialists.
The game's first chance came on three minutes as Thacker was played in behind and forced a great reflex save from Eastwood and Graham made sure to block the follow up.
United had a chance on 11 minutes, but from a Greaves cross, trialist Moore could only loop a header wide of the target.
Hull would break the deadlock shortly afterwards, Yates had an effort from outside the box blocked but CHADWICK fired home the rebound into the bottom corner.
Parity was almost restored midway through the half as a Gilmour corner to the back post narrowly evaded the run Moore.
The Blades thought the equaliser had arrived five minutes before the break but Smith's finish after a cross from the right was ruled out because of an offside flag.
A minute in to the second period United came close again as Moore's blocked effort fell to Cantrill who had a shot deflected into the grateful arms of Foulkes.
The visitors almost doubled their lead on 54 minutes with a good long range strike testing Eastwood, who pulled off a fine save down to his left.
But the Blades stopper was powerless to prevent LEWIS-PORTER moments later, as he turned and fired into the top corner from distance.
Hull would put the game beyond the Blades on 78 minutes as LEWIS-PORTER got his second after a swift counter attack.
Potts came close to a consolation but his shot was well blocked from Smith's squared pass in what was the final action of note.
Blades: Eastwood, Goode (Belehouan 76), Greaves, Ferguson, Graham, Cantrill, Gilmour, Slater, Smith, Moore (Broadbent 72), Parkhouse (Potts 88).
Unused: Warhurst, Weaver.