Thomas Christiansen has conceded that Leeds United were simply "not good enough" in Friday night's 2-1 defeat to Sheffield United at Elland Road.
The Whites somehow found themselves level at 1-1 at the midway point, despite failing to manage a single touch in the opposition box prior to Kalvin Phillips cancelling out Billy Sharp's third-minute opener.
Leeds boss Christiansen was left unhappy with the manner of his side's first-half display in particular, with the Blades going on to earn Yorkshire derby bragging rights thanks to a late David Brooks strike.
"I cannot be happy. Three points is what we want - tonight we weren't able to make it," he told reporters. "We didn't make a good performance and the way we acted in the first half was not good enough. We were still in the changing room when they scored the first goal.
"It's more than attitude, it's concentration. It was a bad first half, we managed to come back in the second half but still not good enough. We predicted their XI, the formation was what we thought, we worked on that, it is my problem that we didn't do it.
"There will be time to analyse the game. I'm very disappointed but this is the league sometimes. This happens and unfortunately it happens in a six-point game. We have to raise our game again."
Leeds remain fourth in the Championship table following Friday's result, while Sheffield United climb top of the second tier for the first time in 12 years.
