Chris Wilder described Tuesday's loss to Fleetwood Town at Bramall Lane as 'a disappointing night'.
Goals from Conor McLaughlin and Devante Cole saw the Cod Army leave South Yorkshire with all three points, to leave the Blades without a win in three matches.
And Wilder admitted afterwards it was a below par performance against a side who are now 11 games unbeaten in League One.
The manager commented: "It is a disappointing night, there is no getting away from that fact, we've lost at home and we've not shown the quality we normal show.
"Fleetwood came with a plan and executed it very well. They are difficult opponents, they are well organised, defend very deep and unfortunately we didn't have the nounce, guile and possibly the personnel to unlock them.
"They score off an attempted shot that's going 25 yard wide, but it falls right at the feet of their lad at the back post, that's fortunate for them and it gave them something to defend.
"The second goal is a poor one for us, it's an individual mistake and they are proving costly at the moment. From there it turned into a tough night.
"Fleetwood deserve credit, we weren't anywhere near out best, we tried to change things round, we tried to score the perfect goal to break them down, but the fact is they defend so well."
Wilder added: "We're on a difficult run, Fleetwood are flying and they enjoyed their victory, hopefully the players heard their celebrations and will bounce back in the right manner.
"But we've been in worse situations than this, we were at the bottom of the league with one point from four games, so we've shown courage previously and we remain in a great position, determined to get ourselves moving forward again."