Jose Mourinho would have been in no doubt that his Chelsea team would face a real challenge to successfully defend their Premier League amid the considerable rise in quality at both ends of the table, but even he has been left surprised by the extremely poor start they have made.

The ‘Special One’ has cut an extremely forlorn and frustrated figure on the sidelines as his team have shown weaknesses in a number of facets of their game that hardly anyone expected of a Chelsea side that dominated the league last season.

They currently appear a distinct shadow of their former selves, with Chelsea regressing from a side that set a new record for the length of time spent at the Premier League summit to one that look defensively vulnerable and lack the spark that made them so formidable throughout the 2014/2015 campaign.

Betway have bumped the Blues down from title favourites to fourth favourites following an extremely poor start which has not only resulted in just one victory and three defeats, but also left Chelsea with the worst defensive record in the league.

It would be rather unwise to rule out the defending champions after just five games, but with early pacesetters Manchester City already eleven points ahead, they may need to sort themselves out sooner rather than later.

It was difficult not to be impressed by Chelsea’s wonderful attacking play as they illustrated the sort of swagger and class you would expect from any Jose Mourinho team, but this was only made possible by the wonderfully resolute defence that kept things extremely tight at the other end.

The entire back four, including goalkeeper Thibault Courtois, were outstanding throughout the campaign, with John Terry and Gary Cahill forming a formidable centre-back partnership that many teams found an impossible obstacle to get around.

Full-back Branislav Ivanovic and Cesar Azpilicueta played an instrumental role at both ends of the pitch, with their willingness to bomb forward with energy and desire adding an extra dimension to Chelsea’s play that opponents found difficult to handle.

Fast forward a few months, and a defence that looked extremely watertight and strong is now vulnerable, error-prone and resembles a collective unit that do not appear to have played together before.

Ivanovic, in particularly, has endured a torrid time against fast wingers who have made the Serbian look distinctly average, while Terry is showing signs of being past his best, with uncharacteristic errors leading to a falling out between the club captain and Mourinho.

Even the recent 4-0 Champions League victory against Maccabi Tel-Aviv failed to tell the whole story; although Eden Hazard blazed an early penalty over the bar to continue his slump in form, the visitors missed several guilt-edged chances as Chelsea’s defence, despite recording a much-needed clean sheet, were all at sea.

It will take a major improvement before Chelsea’s defence is anywhere near the levels that it reached last season, but as they are already playing catch-up in the Premier League, it will have to come sooner rather than later.

Teams who are able to function and click as a collective unit are ultimately the ones that enjoy success and win titles, but it also requires the added ingredient of quality from star players who are able to change a game with individual skill and ability.

Chelsea are undoubtedly blessed with hugely talented players in the form of Hazard, Cesc Fabregas and Oscar, with Diego Costa also offering a real goal threat upfront with his physicality, aggressiveness and clinical finishing touch.

However, none of them have really turned up to the party this season, especially Fabregas who has been in decline for a number of months; his energy and range of passing continues to desert him, and it remains to be see how long Mourinho persists with a player who is currently performing well below his capabilities.

Nemanja Matic has also struggled to assert himself as the defensive midfield lynchpin that provided fantastic protection in front of the back four as Chelsea stormed to the title, with the intensity and pressing that was so prominent about their game being practically non-existent as teams, particularly Everton and Manchester City, have managed to get in between the lines all too easily.

Winning the Premier League title should produce an incredible rise in confidence and determination to carry out the same feat the following season, but it has been remarkable how Chelsea have gone from a superbly drilled team in all aspects of the game to one that appears completely devoid of preparation and match sharpness.

This could prove to be Mourinho’s biggest mistake; his decision to shorten Chelsea’s pre-season preparations has dramatically backfired, and although it is easy to read anything into the fact that they did not win any of their friendlies, they have carried that form into the season and appear a team devoid of confidence, form and ideas.

The performance at Everton epitomised a team who had no real indication of how they wanted to play the game, with the fluid, free-flowing football of last season replaced by slow build-up play that has lacked any real invention and creativity.

There is still plenty of time for Chelsea to transform their fortunes and make their currently title odds with Betway turn out to be excellent value, but they have to rediscover their magic touch pretty quickly before their hopes of defending their Premier League crown have ended before they have even begun.