Chris Wilder admitted his side were second best at The Den, following Saturday's 3-1 loss to Millwall.
David Brooks cancelled out Lee Gregory's opener in the capital, but two second-half goals from the Lions consigned the Blades to defeat in the capital.
And speaking post-match, Wilder made no excuses, conceding his side got what they deserved.
He remarked: "We didn't deserve anything from the game, Millwall were far more effective and deserved the win.
"We're disappointed in the manner of the performance. We told the players what to expect here, but they must have had headphones on when I was speaking, and I'm not pleased with that.
"We scored an excellent goal to get back into the game and dominated the back end of the first-half and beginning of the second-half, but then we get caught on the counter attack and we weren't effective enough.
"I've got no complaints whatsoever, Millwall fully deserved their victory."
The Blades boss added: "The bottom line is we didn't do enough. Whether teams play like us or in their own way, I'm never critical of how teams decide to go about their job.
"What I demand is that we play effective football, we didn't and Millwall did and we couldn't cope with it.
"We put five crosses in from the right in the first-half and nobody has bust a gut to get a tap-in, then we've had opportunities to do the same from the left and we've hit the first man.
"We just weren't effective in our decision making, getting round the first and second balls, the team we picked simply didn't do enough and I don't like what I've seen."