Manchester United had an afternoon to forget on Sunday as they were mauled by Chelsea at Stamford Bridge.

In a performance that made for uncomfortable viewing for Man United supporters, Antonio Conte's Chelsea ruthlessly exposed their weaknesses and romped to an eventual 4-0 victory, laying down a huge marker of their own.

The tone was set when Pedro scored after just 33 seconds of play, and Jose Mourinho's Red Devils never truly recovered. Indeed, the Manchester giants looked rocked by the first goal, which may have somewhat derailed their plans to set up as they did at Liverpool and play defensively for a 0-0 draw.

And following the defeat, there has been plenty of talk that the club could be in serious trouble going forward this campaign – they are now six points off joint leaders Manchester City, Arsenal and Liverpool and five off of Chelsea in fourth spot.

Defensive issues look here to stay

Britain Soccer Football - Manchester United v FC Zorya Luhansk - UEFA Europa League Group Stage - Group A - Old Trafford, Manchester, England - 29/9/16
Manchester United's Chris Smalling
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United's defensive incapabilities were clear for all to see on Sunday afternoon and it's safe to say both Chris Smalling and Daley Blind won't be looking back on this game with any affection whatsoever over the coming days.

The centre-back pairing were pulled all over the place by Chelsea's forward line and with Eric Bailly now out long-term with suspected serious knee ligament damage, Mourinho may have no choice but to continue playing his underperforming defenders.

It's a real worry for the United boss.

They have an inability to compete against the top teams

Chelsea v Manchester United - Premier League

What must be extremely worrying for everyone at Manchester United right now is the fact they just can't compete with their title rivals.

Manchester City have already beaten them in the league. They could only draw 0-0 with Liverpool in a game that was absolutely dire and now Chelsea have battered them. United could really head backwards if they don't start competing with the teams around them.

Sure, they can beat the lesser teams to the moon and back, but if they want to be in with a shot of getting the title, they need to compete with the best, or they'll be left behind.

United's 'stars' fail to show up yet again

Paul Pogba and Zlatan Ibrahimovic

Perhaps what is most worrying of all for both Manchester United's supporters and Mourinho is how their so-called 'big names' are going missing in vital fixtures.

Paul Pogba has copped plenty of criticism for his performances so far this season and whilst there have been glimmers of quality, they have been too infrequent.

The same can be said for Zlatan Ibrahimovic, who was again redundant in the loss against the Blues.

United can't rely on teenagers to carry the team in games like these - the experienced players amongst the group need to step up and stand out.

Otherwise, United have no chance.