Put in no uncertain terms whatsoever, the 2015/16 campaign has so far been an utter disaster for Chelsea and the ever pressured Jose Mourinho. Although no honest Blues fan needs to be reacquainted with such a notion in the cold light of day, something is going seriously wrong at Stamford Bridge at the minute, and few have ultimately been able to place their finger on the direct cause of their dramatic downturn.

The club’s once untouchable manager seems in less control with every passing week, several important stars have failed to turn up at all this campaign – and although the vast amount of the current season obviously remains to be played at this stage in the proceedings – it remains difficult to see just how Chelsea will manage to resurrect themselves before the situation becomes truly untenable.

In light of all the recent disappointment and frustration to afflict the Stamford Bridge faithful, Diego Costa’s notoriously questionable role within Jose Mourinho’s set up has subsequently been thrown into doubt. So far this term, the former Atletico Madrid star has proven largely ineffective to say the very least.

So then, with all that’s already happened to the Blues in this distinctly testing campaign for the Premier League title holders, should Chelsea ultimately persevere with Diego Costa up-top for the rest of the season?

Well, considering Costa's rather lowly looking stats across 2015/16 thus far, maybe Mourinho must look to address the current problems among his striking department after all. The Brazilian-born Spanish international has proven nowhere near as deadly in front of goal as he did last season, his shot technique has seen a severe downturn in accuracy all of a sudden, and the bolshie 27-year-old has also taken far less shots than one would expect of such a high profile striker.

It’s all well and good playing the so-called hard-man of the Premier League when things are going well for your side – but when the going seemingly becomes a little tougher for everyone involved – Diego Costa’s off-ball antics prove rather childish and unproductive within the grand scheme of things.

Ever since the former Atletico man famously got the better of the Gunners’ back-line earlier on this season – a series of incidents in which Arsenal’s Gabriel Paulista was unfairly sent-off after being provoked by the Chelsea centre-forward – the rest of the English top-flight seem to have finally cottoned on to how best to deal with the front-man’s often trivial behaviour. The Spanish international eventually faced retrospective action for his transgressive nature, and as his manager has also confronted a series of recent complaints from his F.A. superiors, the Blues now know that they will be rightly punished for any individual personnel acting out of line.

When any player moulds their approach on supposed ‘gamesmanship’ tactics (or for want of a better word – cheating), and doesn’t rely on pure out-in-out footballing ability alone – they are bound to be found out among their competition one way or another. Although it would be wrong to suggest that Diego Costa is not a smart finisher with strong movement inside the final third, his overall prowess in front of goal is severely limited when referees don’t allow him to carry out all his usual nonsense that normally follows.

The 27-year-old South American therefore fails to prove as effective as he once did among the English top-flight, and is now being rather unflatteringly shown to be a rather pointless addition up-top with all things considered. However, dropping Diego Costa from the first team fold at Chelsea may not be the right call after all…

Even though the front-man has certainly failed to do the business so far this season, he alone is not to blame for Chelsea’s current woes in 2015/16. The likes of Eden Hazard, Cesc Fabregas and Nemanja Matic have also performed poorly this term, as well as the entire Blues back-line letting their manager down time and time again in recent weeks.

In the end, Jose Mourinho should perhaps alter his first team plans somewhat, in order to freshen things up in and around Stamford Bridge this campaign. Maybe the Blues should look to play Loic Remy or Radamel Falcao alongside Diego Costa for once, instead of leaving the Brazilian hit-man isolated up-top on his own every match.

Unless Chelsea see fit to splash out on an undoubted world class talent in the striking department this January – someone who bases their game on scoring goals rather than simply trying to wind up the opposition the whole time – the West Londoners may as well persevere with Costa for the time being. After selling off a series of promising attacking stars in recent windows, Mourinho has ultimately left himself with little choice…