Defeat to Liverpool on Sunday confirmed Manchester United's worst-ever start to a Premier League season.

The gap between the fierce rivals now stands at 19 points, with Liverpool top and Jose Mourinho's Red Devils languishing in sixth.

After winning silverware in his first season at Old Trafford and finishing second last year, Press Association Sport asks where has it all gone wrong for Mourinho and United?

So just how bad have United been this season?

Mourinho's side have won only seven of their 17 league matches this campaign and also crashed out of the Carabao Cup at home to Derby.

While progression into the latter stages of the Champions League was secured, a top-four finish to ensure qualification for next year's competition appears less and less likely – meaning Mourinho's men would have to win this season's edition.

In finishing a distant second to champions Manchester City last season, United conceded only 28 goals, one more than their neighbours, while Sunday's 3-1 loss at Anfield means they have already shipped 29 before the halfway stage this time around.

Newly-promoted Wolves sit just a point behind United in the table and have the same goal difference (0) as the 20-time league champions.

But these are the same players who Mourinho took to second place

Other than Michael Carrick retiring to join Mourinho's coaching staff and squad-player Daley Blind sold to Ajax, United lost no major names during the summer.

Mourinho's main gripe was that the squad he had was not sufficiently strengthened in areas he felt necessary.

The Portuguese was adamant he needed at least one new central defender with the likes of Toby Alderweireld, Harry Maguire and Diego Godin all linked with Old Trafford – but nothing transpiring.

Instead, United signed teenage full-back Diogo Dalot, Brazil midfielder Fred and 35-year-old goalkeeper Lee Grant as back-up to David De Gea and Sergio Romero.

It remains to be seen if – given the poor start – Mourinho is backed in the January transfer window but it is notoriously difficult to land big-name players during the season.

How can they be in such a poor position compared to last season?

While United have largely stood still after a fairly quiet summer of transfer activity, their rivals have all improved.

Liverpool now top the table after recruiting in areas where they have struggled in recent times – centre-back Virgil Van Dijk came in last January but goalkeeper Allison Becker, midfield pair Naby Keita and Fabinho and Xherdan Shaqiri – who came off the bench to score the match-winning brace against United – were all signed in the summer.

Champions Manchester City strengthened with Riyad Mahrez, while continuity at Tottenham keeps them above United and a change of manager and approach at both Chelsea and Arsenal has seen them leapfrog Mourinho's men so far this campaign.

So are the players who were already there not meeting their standards?

Mourinho insisted after the Liverpool defeat that his players were not "dishonest" and that they were giving their all for him and the club.

Instead he simply said Liverpool are currently better than his team, something that was echoed by former United captain Roy Keane as he worked as a pundit for Sky Sports.

Paul Pogba, the club-record signing, was an unused substitute as the visitors chased the game on Sunday but the World Cup winner is still yet to hit the heights of his Juventus days since returning to the club in 2016.

Romelu Lukaku's goal in the recent 4-1 home win over struggling Fulham was his first at Old Trafford since March, while Alexis Sanchez remains injured following a dismal start to his United career.

It is the players who are at fault?

Mourinho has to shoulder most of the blame. While he did not get the backing he felt he required in the last transfer window, United have spent big since the former Chelsea boss replaced Louis Van Gaal.

Big-money centre-backs Eric Bailly and Victor Lindelof are still yet to nail down a place in Mourinho's team, while the Portuguese seemingly remains locked in a power struggle with Pogba.

There are rumours of a rift with Antonio Valencia, a player who was regularly wearing the captain's armband for Mourinho in recent times.

Jose must go then, right?

Having signed a contract extension in January, tying him to United until 2020 – it would cost the club a significant amount of money to remove Mourinho from the helm.

His second spell at Chelsea ended with the sack in December 2015 after a run of nine defeats in 16 league games as defending champions, and an unhappy festive season could yet see United's board act before the transfer window opens.

There is never much goodwill in the bank for a manager who sets out his side in a manner which does not promote attractive football and Mourinho rarely does that.

He will point to not having the players available to do so, and to an extent he is right – especially when you factor in the number of injuries the club have contended with.

United supporters, especially those who travel to watch the team away from home, still seem to be behind their manager but that could change if things get worse. Watch this space.

But can it be turned around?

There is currently an 11-point gap to Chelsea in fourth but if Mourinho can inspire his team to put together a winning run they could still close in on the Blues if they drop points.

The trouble is the likes of Spurs, Chelsea and Arsenal – let alone Liverpool and City – look much better equipped to rack up points over the busy Christmas period than United, who have not won three league games in a row since March.

Splashing the cash in the right areas in January would also bolster the hopes and belief around Old Trafford, while Mourinho adopting a more attacking philosophy may keep some detractors on side for longer.