Plenty of managers have claimed that it is always much harder to defend a league title rather than win it in the first place.

Chelsea’s current form would certainly affirm that statement, as the first two games of their Premier League defence have yielded plenty of controversy but only a solitary point - which sees them already five adrift of most of their main rivals.

Of course it is very early days in terms of the season and the Blues will no doubt be competing at the business end of the table come the Spring.

What though are the main causes of concern connected to the sluggish start for fans at the Bridge?

Here's three that spring to mind...

Cracks at the back

John Terry

Claiming the title last term was of course a combination of many factors but the solid foundation of Chelsea’s back four was without doubt one of the most important.

This season though, the champions have leaked five goals in their opening two games. Few will be panicking as such an imperious rearguard could simply not just deteriorate over one summer.

For all their impressive displays however, the Stamford Bridge backline were extremely lucky last term; not on the field of play, but that they remained intact throughout the season.

The West London outfit suffered no major injuries at the back last year.

Jose Mourinho has obviously identified the need for cover, opting to bring in Augsburg left-back Baba Rahman and go after Everton’s John Stones.

The high profile half-time substitution of John Terry in the defeat to Manchester City was seen by many as an attempt by the manager to persuade owner Roman Abramovich of the need for reinforcements.

The first choice four of Terry, Cahill, Ivanovic and Azpilicueta will also have an average age of over 30 by Christmas. While they are all still fantastic players, fresh blood may be needed to keep them at the top of their game.

A warring Mourinho

Mourinho

In good times or bad there is rarely a week that goes by when the boss isn’t in the media spotlight for something that he’s said or done.

At the moment there are plenty of signs that Jose’s toys are well and truly out of the pram.

His decision to substitute Terry last weekend had all the hallmarks of a manager trying to make a statement.

It was the first time during either of his two spells at the club that the Portuguese decided to withdraw his captain from the field of play. The manager claimed tactical reasons but plenty of pundits highlighted that it looked like Mourinho had an axe to grind.

He’s certainly been grinding it with his staff having publicly disciplined club doctor Eva Caniero. Then there is, of course, his favourite sparring partner, Arsene Wenger.

Mourinho has continued to participate in a row with the Arsenal boss that seems destined to drag on for eternity. The problem for Chelsea here is not the Mourinho soap opera itself, but the reason why he is acting it out.

Throughout his career the 52-year-old has always been at his most fractious, no doubt intentionally, when he smells complacency or sees the need to shake things up. The atmosphere within his first team circle must be worrying him; therefore his activities should be worrying Chelsea fans.

Sky Blue Blues

Manchester City v Chelsea - Barclays Premier League

Most concerning perhaps for the club’s supporters and Mourinho though is a factor out of their control entirely.

Manchester City mean business.

Their rivals from the north west and champions of the previous season look to be hungry and on form. Standing out like an ominous warning beacon from the Citizens’ impressive start is midfield talisman Yaya Toure.

When City last won the title, the big Ivorian was their driving force; an almost unplayable midfielder. Last year he looked disinterested at times and Chelsea were allowed to canter off into the distance.

This year will be different. Manuel Pellegrini’s side crushed their rivals in the first heavyweight clash of the season, giving them a clear psychological edge.

City have reinforced their squad for a serious title charge and this week sealed a move for impressive Argentine defender Nicolas Otamendi.

If they can add Chelsea cast-off and Bundesliga player of the year Kevin De Bruyne before the window closes it will give them another massive boost.