Paul Pogba says Manchester United need to "change something" after being beaten 4-2 by Leicester, their second defeat in three Premier League games.
United have taken one point out of a possible nine, dropping to fifth and losing ground in the title race.
There have also been several other unconvincing performances this season.
"We have been having these kind of games for a long time and haven't found the problem. We have conceded easy and stupid goals," Pogba told Sky Sports.
"If we want to win the title, these are the games we need to win, even if they are very hard.
"We know that the fans were going to push and put pressure on us and we need to be more mature, play with more experience and arrogance - in a good way - by taking the ball and playing our football.
"We need to find the key for this change because we deserved to lose. I don't know if it is the mindset of the players. We need to change something. We need to find the mentality and tactics to win. We have to look as individuals and as a team to fix this."
United's latest disappointment ended an unbeaten away league record spanning 29 games and 20 months.
It contained all too common themes for their supporters, with the team failing to control the tempo of the game in the middle of the park and conceding from dreadful defensive lapses.
"We more or less gifted them the equaliser," said United manager Ole Gunnar Solskjaer.
"The second one was a set play, which is disappointing. Then you get the equaliser... and 10 seconds after you concede again. So concentration in big moments, that's a key factor in this game."
Leicester's first goal came from United's own free-kick on the edge of their penalty area after Harry Maguire was caught out.
The visitors also twice let in goals from set-pieces, while Leicester's third, 54 seconds after Marcus Rashford had equalised, came when Aaron Wan-Bissaka's poor positioning was finally exploited by the hosts, with Jamie Vardy the beneficiary.
"The whole performance was not good enough with the ball and without the ball. Over the international break we have had a good time to see what has gone wrong lately," Solskjaer added.
"We have had too many games where we have lost points, so we need to look at the whole set-up of the team, the whole balance of the team, and maybe something has to give.
"Every point in the Premier League you have got to fight for. You have got to win second balls, you have got to tackle, you have got to block, you have got to win headers, and in key moments today we just didn't block or defend well enough or even attack well enough.
"Every game is a test of character here. Especially now, it is an examination of character, staff, players and everyone around here, that we stick together and fight on Wednesday night."
United face Atalanta in the Champions League on Wednesday, before hosting in-form Liverpool at Old Trafford on Sunday.
The United manager added: "It says everything our best player was David [De Gea] but we still conceded four goals.
"We've got to dust ourselves off and make sure that when we come in again with that fresh in their minds, they look themselves in the mirror, I've looked myself in the mirror, and make sure we perform again."
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