Chelsea's preseason form a worry ahead of Premier League kickoff

We talk Diego Costa's impact in Chelsea's performance last season and believe he remains a key player for the club next season.

In terms of results, Chelsea's preseason has not been especially productive. Four games and no wins inside 90 minutes has given rise to many questioning their relative inactivity in the transfer window and the decision to play so few games in the build-up to the new campaign. There is still one more match against Fiorentina to play on Wednesday night, although even a thumping win is unlikely to satisfy those for whom the glass is half empty.

Another way to look at it could be this: Contrary to the attitude of some other clubs, wins in preseason are not what Chelsea specifically set out to achieve even if losing to Arsenal is never palatable. Getting minutes into the legs of the whole squad and experimenting with lineups and formations are the primary objectives of the coaching staff. In any case, the Blues have played three strong Champions League teams in those four games and drew with two of them before winning on penalties. Hardly a disaster.

Ultimately, though, none of these games matter a jot. The only concerns will be if Chelsea bring the sloppiness they showed in the Community Shield into the start of the Premier League season. If they do, then they have been handed an opening set of matches that will certainly exploit any weakness.

Swansea at home might not be the toughest fixture with which to begin the defence of their crown, though neither are they any pushovers. Last season the Welsh side took the lead at Stamford Bridge and gave the Blues a real run for their money until Diego Costa's 22-minute hat trick turned things in favour of the home team.

Eden Hazard and Chelsea have yet to truly click this preseason.

The following weekend will provide arguably the toughest examination of the lot when Chelsea travel to Manchester City. Both matches last season ended as draws with the Londoners throwing a lead away on both occasions. With £49 million having been spent on extricating Raheem Sterling from Liverpool, the Citizens have shown they mean business and will be determined to claim the champions' scalp even before you consider the deep antipathy that Manuel Pellegrini has for Jose Mourinho.

After that comes a trio of fixtures that on the surface appear to be rather benign but have proved to be anything but in recent years. West Bromwich Albion have proved a constant thorn in Chelsea's side and have caused problems for a series of managers. Defeat at the Hawthorns proved the undoing of Andre Villas-Boas and Roberto Di Matteo, while last season even Mourinho suffered the experience of losing there -- albeit after the title had already been assured. Tony Pulis has history of beating the Special One, adding further to the intrigue.

Hot on the heels of that game comes Crystal Palace's visit to Stamford Bridge for a London derby. The Blues have happy memories of last season's corresponding fixture as the 1-0 win mathematically guaranteed that Chelsea became champions, although they were made to sweat by a Palace side that pressed for an equaliser until the final whistle.

The international break then arrives before two more extremely challenging games. Everton away is rarely a cakewalk for Chelsea, even if last year's 6-3 scoreline might suggest otherwise. Goodison Park always seems to be pumped up for this fixture, which might have added spice this time if the visitors' have been successful in their pursuit of centre-back John Stones. With former Chelsea striker Romelu Lukaku also having appoint to prove, it will be a real examination.

And then comes Arsenal. Although the Gunners start every season confident that this will be their year, this time there might just be a little more substance to their claim after the signing of Petr Cech. Alternatively, by the time they come to West London in mid-September, they might have suffered their traditional early-season malaise and already be under pressure. Either way, it will be a contest that will be all about winning, irrespective of the performance.

After that comes a series of matches that Chelsea should expect to win if they are to retain their title. That, however, will be made much more difficult if they make a hash of of their opening six fixtures. Setting the tone for the season early on is vitally important and something that Mourinho's men did admirably last season. The fast start that saw Costa's prolific goal scoring blow successive opponents away injected fear into the chasing pack while sending confidence surging through their own squad.

Performances in preseason might not suggest that they are quite in that frame of mind or body at present, but there have been glimpses that it might just manifest itself before long. In passages against both Barcelona and Arsenal, Chelsea showed that the rhythm that won the Premier League title in such convincing fashion is still very much in existence. If they can begin to harness it for the duration of the 90 minutes then the Blues can hope to be quick out of the blocks once again.

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