With the four clubs taking a combined 49 points from their first eight games - the fewest between them since the first Premier League campaign in 1992 and far fewer than in recent seasons - we take a look at the problems they have been facing.

Manchester United: Baby blanket

After taking just nine points from their first eight games - their lowest tally at this stage since 1989 - Manchester United are the obvious culprit for this collective drop in points. And with just nine goals scored, it's clear where their problems lie.

With their youngest-ever starting XI in a Premier League season, the club have actually had the fifth-most shots in the league, but it's the quality of those shots that are the cause for concern.

According to expected goals, only Newcastle have had worse shots on average than Ole Gunnar Solskjaer's young side, outside of penalties.

One positive for United fans is that while the attack is struggling to create good chances, the defence has restricted the opposition's opportunities, making it one of the best defences at this early stage.

After spending £130m on defenders Harry Maguire and Aaron Wan-Bissaka and selling striker Romelu Lukaku over the summer, this is perhaps no real surprise.

Tottenham: It's complicated

On Valentine's Day, Tottenham were third in last season's Premier League and just five points behind leaders Liverpool.

But 22 points from 20 games since then has put a strain on the relationship between the manager, players and the club, with talk of an "unsettled" squad and some reportedly looking to catch the eye of other clubs.

The difficulty for Tottenham is that it's not one specific area of the team that is the problem. As well as the players not pressing like before, the table below shows that both the defence and the attack so far are as bad as they've been at this stage in the six seasons under Mauricio Pochettino.

While it is impossible to know for sure, this could be down to the fact the manager and players have been together for an unusually long time. Eight players are still at the club from Pochettino's first season in 2014-15 - compared to just three at Manchester City and two at Liverpool - while of the 32 managers in the Champions League this season, only Atletico Madrid's Diego Simeone has been at his club longer than his fellow Argentine.

Arsenal: Gunners under fire

With the club currently third in the table, it may seem strange to say that Arsenal have had problems this season. But a goal difference of +2 suggests that all is not as comfortable as it seems, with no team having sat as high in the table with so low a figure at this stage since Phil Brown's Hull City did so with a goal difference of zero in 2008.

After allowing 10-12 shots per game in each of the club's final 13 seasons under Arsene Wenger, they allowed just over 13 in their first campaign under Unai Emery last season. This season, however, Arsenal are currently allowing a remarkable 17 shots per game, with only promoted sides Aston Villa and Norwich having faced more shots than the Gunners this season.

The one consolation for Arsenal fans is that while the team has been under heavy fire this season, they have managed to prevent the opposition from getting good shots away, with only Burnley allowing lower-quality chances than Emery's side on average.

Even so, in the previous five seasons before this one, only three sides have allowed 17 or more shots per game - Sean Dyche's Burnley twice and David Moyes' relegated Sunderland side in 2016-17.

Chelsea: Kepa could do better?

Although Chelsea's youngest-ever starting XI in a Premier League season has been praised by many, it has also conceded an uncharacteristic 14 goals in its eight games so far, with only Norwich, Watford and Southampton letting in more.

It is only the second time in the Roman Abramovich era that the club have conceded double figures at this stage of the season, after the club's meltdown under Jose Mourinho saw them concede 17 goals in their first eight games in 2015.

Having saved just 48% of the shots he's faced this season, keeper Kepa Arrizabalaga has the worst save percentage in the Premier League so far and takes some share of the responsibility for the club's defensive woes.

Of the 25 goalkeepers to have played this season, only Southampton's Angus Gunn has conceded more goals than expected than the Chelsea keeper.

The blame cannot be laid entirely at his door. Despite only Manchester City facing fewer shots so far this season, only four sides have allowed the opposition easier chances to score on average than Chelsea, so Frank Lampard will be hoping his youthful side can make Arrizabalaga's job a little easier in future.