Manchester - Jose Mourinho accused his Manchester United players of lacking heart after their hopes of a push for the Premier League's top four were dented by a lethargic 0-0 draw against Crystal Palace on Saturday.
Mourinho's side were booed at the end of a match that left them seventh in the table, well adrift of the Champions League qualification positions.
Paul Pogba was unable to inspire United on his return from a muscle injury, playing for 67 minutes before he was replaced by Alexis Sanchez, with Mourinho left frustrated that his attacking selection had failed to produce enough to break down obdurate opponents.
The Old Trafford stalemate was the first of eight games United will play in the league between the recent international break and the end of the calendar year.
Mourinho had been hopeful a strong showing would help to build the momentum that could carry them back into the top four before 2019 begins.
Instead, he was left to warn his players that a similarly lethargic showing at home to Swiss side Young Boys on Tuesday could leave United struggling to progress from this season's Champions League group stages.
Mourinho claimed that his players should have treated the Palace match as "special", arguing that they failed to do so.
"If we play with the same philosophy against Young Boys, then we won't win and we will have to go to Valencia (in the final Champions League group game) and win there," he said.
"There are games that are special games and not just one more match. This was a special game, the first of eight Premier League games before the end of December and one we needed to win.
"There was not enough from the heart. You must play with brain and also with heart and I think there was not enough heart."
Mourinho's frustration was evident at the lack of clear chances created.
Romelu Lukaku, who has not scored for United since September 15, had a goal disallowed early in the second half when he was judged narrowly offside as he tapped in a loose ball following goalkeeper Wayne Hennessey's save from an Ashley Young shot.
Palace, however, had already had a goal of their own ruled out by a similarly tight offside call shortly before the interval, when Cheikhou Kouyate diverted in Luka Milivojevic's free-kick with his shoulder.
Patrick van Aanholt failed to take good chances in either half for the visitors, with Andros Townsend steering just wide in the final 15 minutes after a bludgeoning run through the United defence.
United's performance led Mourinho to question whether his players would be as disappointed as him about the result.
"There are people that will have a bad dinner, there are people who will have a nice dinner and there are people who will have a party," he said.
The match's other main talking point saw Marouane Fellaini, just on as a United substitute, escape without a booking for a reckless challenge on Milivojevic.
Palace manager Roy Hodgson, though, preferred to focus on the positive side of a performance that suggested his team's eight-match winless run will end sooner rather than later.
"At least today I have got the satisfaction of believing the team played extremely well," he said.
"At least we got something and on another day, if fate had been kinder and we had been a bit more clinical, we could have won it.
"There aren't many teams in our part of the table that will come to Old Trafford and win and even fewer that will come and get a point in the way we did today."