Erik ten Hag blasted his "inconsistent" Manchester United charges after Bournemouth made history with their first ever victory at Old Trafford on Saturday.
Ten Hag's side slumped to an embarrassing 3-0 defeat that underlined the array of problems threatening to ruin United's season.
Just three days after beating Chelsea to revive their bid for a top four finish in the Premier League, United reverted to the sloppy form that has plagued them for much of the campaign.
Goals from Dominic Solanke, Philip Billing and Marcos Senesi handed Bournemouth a memorable win as Ten Hag and his players were booed off at fulltime.
With the pressure mounting on Ten Hag with each defeat in his troubled second season as United boss, the Dutchman slammed his team's lacklustre performance.
"Of course, annoyed and disappointed, definitely. I expected something different," Ten Hag said.
"I hoped before the game you can build on the performance and result from Chelsea, so then it's very disappointing.
"That (consistency) is of course the question, but I think we have to always be ready for the game, so I have to take the responsibility for that.
"I have to prepare my team so that they are ready for the game, so from my point of view I'm very disappointed the way we started so I have to do the things better."
🗣️ Erik ten Hag's post-match reaction.#MUFC || #MUNBOU
— Manchester United (@ManUtd) December 9, 2023
United have now lost 35 home league games since Alex Ferguson retired at the end of the 2012-13 title-winning season.
During the iconic 26-year reign of the Scottish manager, United were only beaten in the league at Old Trafford 34 times
Ten Hag shouldered much of the responsibility for United's 11th defeat in all competitions this term.
But alarmingly for United fans, the former Ajax boss conceded he did not believe his squad were consistent enough to thrive at the highest level.
'WE AREW NOT GOOD ENOUGH'
"We are really inconsistent. We have the abilities to do it, but you have to do it every game and every third day," he said.
"I think as a squad we are not good enough to be consistent and we have to work as a squad to improve that."
It was an eye-catching remark at the end of a week that began with reports that some United players had grown unhappy with the manager.
Ten Hag denied those claims but, with his team mired in sixth place, he desperately needs some positive results quickly.
United host Bayern Munich in the Champions League next week knowing they must win to have any chance of progressing to the last 16.
A trip to in-form Liverpool in the Premier League follows the Bayern clash.
"As a group, we have to improve," Ten Hag said. "That's a fact. We have to get tougher, that we are ready for the game and from the start.
"I said on Friday, it can't be in this league that you are not playing on the highest levels because you get killed.
"That's what happened in the five minutes and then you are following facts and especially against them, such a good transition team, you make life easy for them. They have the perfect conditions to play in.
"Then you see the team fighting, battling, put a lot of effort in for a long period to return in the game, but it can't happen that you so easily concede a goal."