Following United's exit from the FA Youth Cup at the hands of Preston North End at the third-round stage on Wednesday evening, Lead Coach Derek Geary admitted it was 'a big opportunity missed'.
A penalty in just the fifth minute of the contest, converted by Melle Muelensteen, proved decisive for the Lilywhites at Deepdale, despite the Blades dominating the game, particularly in the second-half, in which Jordan Hallam had a goal ruled out for offside.
Speaking exclusively to sufc.co.uk, Geary remarked: "I'm gutted for the boys because this is such an honest and hardworking group and we deserved to progress.
"We were the better team on the night and did everything but score. We made one mistake early on and it's proved costly, so this is a big opportunity missed.
"The FA Youth Cup is a fantastic competition, but it is unforgiving, it's knockout football and unfortunately we don't get a second chance.
"I believe in the squad and I honestly thought we could progress further in the competition and do ourselves justice against the biggest clubs in the country if we'd got the opportunity.
"But it just wasn't meant to be and we now have to react positively moving forward.
"We're currently top of the Professional Development League and the aim must be to remain there and set up an exciting finale to the season."
The former United favourite added: "It is a steep learning curve for these boys, the older ones will hopefully progress into the U23s and beyond, whilst the first-year scholars will be feeling the hurt of this until next season.
"For me my biggest learning curves were my mistakes and I hope my experience will help the lads overcome this obvious disappointment because losing doesn't get any easier to take as a coach as it did as a player.
"I'm a bad loser, I hate it, there were a few tears in the dressing room at Preston and that shows just how much this competition and club means to our youngsters."