Liverpool's nightmare January reached rock bottom as they were dumped out of the FA Cup in the fourth round by Wolverhampton Wanderers at Anfield.

Jurgen Klopp's side have won only one game out of eight since the turn of the year - an unconvincing third-round replay win at League Two Plymouth - and the loss at home to a team lying 18th in the Championship leaves Liverpool's season at a tipping point.

Wolves' victory also left Liverpool contemplating the damaging statistic of three successive Anfield losses for the first time since October 2012, the league defeat by Swansea followed by their EFL Cup semi-final exit at the hands of Southampton.

Klopp's Liverpool were riding a wave of Anfield optimism backed up by thrilling attacking football in the early months of the season - so what has gone so badly wrong?

Klopp and Liverpool's dry January

Liverpool saw in the new year celebrating a victory over Manchester City at Anfield that left them in second place in the Premier League just hours before 2016 became 2017.

Klopp and his players celebrated extravagantly in front of the Kop after beating a City side regarded as title rivals. There has been nothing to celebrate since.

The last time Liverpool lost three games at home in succession it was to Arsenal and Manchester United in the Premier League and Udinese in the Europa League at the start of Brendan Rodgers' reign - and the last time Klopp suffered a similarly miserable fate was in April 2007 when he was in charge of German side Mainz.

Liverpool's struggles started when they were held 2-2 at Sunderland on 2 January and momentum has been totally lost since.

Klopp's side were deservedly beaten by Southampton over two legs and he cannot make any serious complaints about fixture overload because the lengthy trip to Plymouth for that third-round replay was a product of selecting a scratch side for the first game at Anfield.

Liverpool performed creditably in a 1-1 draw at Manchester United but the past seven days have been easily the worst since Klopp took over from Rodgers in October 2015.

They close January 2017 facing Premier League leaders Chelsea at Anfield on Tuesday. It is Liverpool and Klopp's last chance to salvage comfort and hope from a dreadful month.

Where has it gone wrong?

Liverpool, so full of threat and intensity until the turn of the year, have looked laboured and lacking in threat and confidence in January.

The most obvious mitigating circumstance has been the loss of leading scorer Sadio Mane to the Africa Cup of Nations with Senegal. The £34m summer signing's stock has risen higher than Anfield's new main stand in his absence.

Liverpool won 15 out of 21 games with Mane but only three out of 10 without him. They lost five out of 10 without him and only one out of 21 when he was in the side. The statistics speak for themselves.

Ave goals for Win % With Mane 2.6 71.4 Without Mane 1 30

Mane offered width, menace and the sort of pressing on opposing defenders that Klopp sets such store in. And most of all he offered goals, nine of them in the Premier League before he left for the Africa Cup of Nations.

This cannot be offered as the sole excuse for Liverpool's collapse, with Klopp still able to call on Daniel Sturridge and Divock Origi, as well as being able to use Roberto Firmino, with eight league goals, as the point of Liverpool's attack.

There is no question, however, that Origi's confidence has fallen through the floor and Sturridge's more languid style simply does not fit the Klopp template. Mane could not have gone on international duty at a worse time.

Liverpool's all-action style was one of the trademarks of Klopp's credo as a manager. He wants a fiercely physical "gegenpressing" approach, pressuring the opposition into submission.

It is a style that makes strong demands upon his players and they have been carrying out his orders to the letter - but is it starting to catch up with Liverpool?

In the Premier League this season, Liverpool have covered 2,579.5km, more than any other team. That's more than 200km further than one of their direct rivals, Manchester United.

Klopp dismisses suggestions he has run his players into the ground and left them exhausted so early in the season - and he would appear to be right. Even through a hectic January, Liverpool remain the team to cover the most distance in the league.

So if they are still outrunning all of their top-four rivals, there are other factors he may point to for this loss of form.

Philippe Coutinho, Liverpool's most creative attacking force in the early phase of the season, is still working his way back after a seven-week absence with an ankle injury, while there is the curious case of defender Joel Matip.

Matip was sidelined with an ankle injury after an impressive start to his Liverpool career following his summer arrival from Schalke - but his return was then delayed after confusion about his eligibility following his decision not to play for Cameroon in the Africa Cup of Nations.

He was back for the midweek loss to Southampton but Liverpool have not lost a game he has started in the Premier League, testimony to his importance. Matip has figured in 13 Premier League matches in all and Liverpool have lost two out of nine without him.

Ave goals conceded Points per game Win % With Matip 1.1 2.2 61.5 Without Matip 1.4 1.9 55.6 Premier League only

All can be offered up as reasons for the sudden downturn in Liverpool's fortunes - but the bottom line is both Klopp and his players have lost the assured touch that accompanied them until the new year.

The Sturridge conundrum

Sturridge's contribution to Liverpool's latest Anfield misery was a 25-minute appearance as a substitute for Firmino - but there is no doubt the England striker is increasingly under the microscope.

The 27-year-old was expected to assume a greater share of responsibility in Mane's absence but, like so much of his career under Klopp, it has simply not happened for him.

The big chance, or chances, came and went for Sturridge in the second leg of the EFL Cup semi-final when two opportunities he would surely have converted with ease in full confidence were badly missed.

And as Klopp has suggested, it is Liverpool's wastefulness in front of goal that is costing them dear. They are still creating chances, but Sturridge and his team-mates are not taking them.

Sturridge's style, relying on instinct and a glorious natural talent, also seems to be an uneasy fit with what Klopp requires. Despite words of support from his manager, he now seems incapable of operating at the level of full-throttle intensity demanded by the German.

The statistics again back up the theory. He recovers possession less often than any other Liverpool player and wins fewer duels against opponents than any other outfield player at Anfield. These are two key components of the classic Klopp tactical plan.

Former Liverpool defender Jamie Carragher delivered a forensic critique of Sturridge's current status in his role as a Sky Sports pundit after the loss to Southampton.

"Sturridge is not the player to run in behind," said Carragher, "so you can forget about him replacing Mane. All he does is come to feet now.

"More often than not you cannot question his finishing but he doesn't do anything else in a game now, whereas he did when he first arrived.

"That's the case with that type of striker now. If they're not a target man or don't run in behind, everything has got to be put on a plate.

"So when he doesn't score you're basically down to 10 men because they're not offering anything else whatsoever."

Klopp has been supportive of Sturridge but the recent Liverpool troubles have underscored the impression that he is starting to look like a square peg in a round hole at Anfield.

How much is Klopp to blame?

Liverpool's manager said it himself after suffering Anfield's displeasure in the wake of the humiliating home defeat by Wolves, accepting he was "100% responsible."

Former Liverpool defender Mark Lawrenson, who was an Anfield, told BBC Radio 5 live moments after Wolves' win: "At 1.20pm today, Klopp found himself at his lowest point since he became Liverpool manager."

Klopp's popularity has soared from the moment he arrived at Anfield in October 2015 after his sabbatical following his departure from Borussia Dortmund.

It was enhanced by taking Liverpool to cup finals in his first campaign, even though they lost on penalties to Manchester City in the League Cup final and were well beaten by Sevilla in the Europa League final.

There is no doubt, though, that he has not covered himself in glory in this unexpected fall from grace.

Klopp has endured scrutiny with some of his selections, including his ploy of leaving the influential Georginio Wijnaldum out of the EFL semi-final second leg loss to Saints. Instead he employed the midfield duo of out-of-form Emre Can and captain Jordan Henderson to little or no effect.

I am responsible, I'm sorry - Klopp

Liverpool's manager has been playing with fire in the FA Cup this season and got his fingers badly burned against Wolves.

Klopp fielded a second-string side in the third-round tie at home to Plymouth and had to settle for a draw, adding an extra game Liverpool would not have relished.

And at Anfield on Saturday, even after the EFL Cup exit to Southampton left the FA Cup as Liverpool's main hope of a trophy, Klopp made nine changes. He tempted FA Cup fate and fate could not resist.

Surely after the disappointment of going out to Southampton one step from Wembley, this was an occasion to ditch that policy in favour of trying to keep Liverpool on track for a trophy?

Klopp could not even offer up the demands of European football as a reason for resting many of his stars, with Liverpool free from that obligation this season.

Yes, Chelsea come to Anfield in the Premier League on Tuesday but the FA Cup fourth-round tie had suddenly assumed a significance Klopp did not appear to fully grasp.

BBC Sport's Match of the Day presenter Gary Lineker made his feelings clear external-link when he said: "Don't get Klopp playing the reserves with no European football. Shows a lack of knowledge of the depth in English football and respect."

This week's events should not disguise the fact that the huge majority of Liverpool supporters are happy the club is in safe hands with Klopp. He retains the affection of the club's fanbase.

Liverpool's owners, Fenway Sports Group, share that view after awarding him a six-year extension to his contract in July last year.

What is in no doubt is that this has been a dreadful week for him and Liverpool - and some of the wounds have been self-inflicted.

How can Liverpool put it right?

Liverpool's goal at the start of the season would have been a top-four place. This was a feat many thought would prove beyond them.

Klopp perhaps raised expectations almost too high with Liverpool's results and thrilling performances earlier this season. This has made the fall from a height even more painful and surprising.

He still has that top-four objective well within reach but he will want marksman Mane back as soon as possible and he will need to work on regaining the confidence and impetus that has been lost.

Liverpool can still achieve big things - but trophy hopes look to be over for another season.