Unless we tighten up and concentrate for longer periods then we'll leave ourselves open
In what was their first game since the Christmas break, Blues went in front just after the half-hour mark when Cameron Ebbutt (pictured) got on the end of a free-kick and forced the ball home.
But they failed to build on that advantage and the table-topping Blades scored three times without reply; including a second-half penalty.
Academy Coach Steve Spooner had no complaints about the result and admitted that his side need to improve defensively.
“We started slowly which was strange, because they had been very quick and sharp in training, and we could have been 2-0 down inside the first 10 minutes,” said Spooner.
“After that we got into the game and started to enjoy the lion's share of possession and passing the ball well.
“We scored but within three or four minutes Sheffield were level through us not paying attention to a throw-in, which resulted in us conceding a free-kick and then an equaliser.
“The second-half took a little bit of getting started again and we conceded a penalty and they took the lead.
“At 2-1 down we had a decent spell and caused them some problems and their keeper had to pull off two really good saves, one of which came from Odin Bailey. If they had gone in the momentum would have shifted.
“The fact is we conceded too easily again and we got what we deserved, unless we tighten up and concentrate for longer periods then we'll leave ourselves open.
“I thought we had nipped that in the bud a few weeks ago, but perhaps we need to be doing some more work on that.”