Manchester - Jose Mourinho acknowledged on Friday Manchester United's current run of form is unacceptable as he battles to turn around their season.
The 55-year-old Portuguese is under enormous pressure, with United in their worst position after seven league matches since 1989 - they are 10th, nine points adrift of the top two Manchester City and Liverpool - and a public dispute with star player Paul Pogba has sewn discord in the dressing room.
His side are looking to end a run of four home matches without a win - their worst run at Old Trafford for 29 seasons - when they host Newcastle in the Premier League on Saturday.
Mourinho is adamant United will improve on their current league position of 10th but he accepted their form at present is not good enough.
"Yes, I accept," he said, although he refused to answer when asked if he could assure the fans he was doing everything he could to improve their form.
Mourinho has endured a testing week, following up a 3-1 league defeat at West Ham last Saturday with a goalless draw at home to Valencia in the Champions League on Tuesday.
Asked why things were not working for United at present, the manager said: "For many different reasons."
He was then asked if he could give the reasons, and responded: "No."
The manager faced heavy criticism for playing midfielder Scott McTominay in a three-man central defence at West Ham, and the sense of turbulence intensified over a social media controversy involving club captain Antonio Valencia.
Valencia had to apologise after liking an Instagram post calling for Mourinho to leave his job. The defender claimed he had not read the text of the post before liking it.
United's home form is a cause for concern at present. They have not won at Old Trafford since beating Leicester on the opening weekend of the Premier League season.
Their longest winless home run before this came between November 1989 and February 1990, when they went six games without a victory at Old Trafford.
Mourinho acknowledged that it was vital for United to improve that home form quickly.
"In many of the leagues the tables in September and October don't reflect what is going to happen in a few months or even at the end of the season," said Mourinho.
"But we are in a position that we can do much better and to do that we need points, points that we lost, especially in the last two Premier League matches, when we took one point out of six.
"We know that to improve that position we need to win these three points (against Newcastle) but we know that our opposition also need the points."
Mourinho, in analysing United's recent form, claimed they had lost one of their past seven matches in all competitions, although that relies on categorising September's League Cup defeat on penalties by Derby County as a draw.
"We have had only one defeat at home all season, only one defeat in the last seven matches but no victories at home in the past three matches, three draws.
"We have not had the feeling of the defeat but not the happiness of the victory so is important for us to try and win this match on Saturday."