Things went from bad to worse for Premier League champions Chelsea on Saturday as they endured yet another defeat - this time at the hands of London rivals West Ham.

That's five league defeats already for the west London outfit this season, who are now in 15th place and eleven points behind table toppers Manchester City, with their title defence seemingly over barring a minor miracle.

Inevitably, the pressure is mounting on manager Jose Mourinho to somehow turn it all around, with the tabloids claiming he could be sacked if the Blues lose to Liverpool on Saturday.

It's a scenario that seemed absurd just a matter of months ago but is now becoming increasingly plausible, which begs the question of who could potentially succeed the Special One at Stamford Bridge. Or perhaps more accurately, who can fix the mess he's created?

With that in mind, Football Fancast take a look at the FIVE strongest candidates...

GUUS HIDDINK

Guus Hiddink

The man who steered Chelsea back onto the right path after the mess Phil Scolari left behind in 2009, going on to win the FA Cup that year, the Blues could turn to 'Aussie Guus' in an interim capacity once again should they give Mourinho the boot.

The 68 year-old earned that moniker during his short but successful stint as Australia boss, leading them to the 2006 World Cup's round of 16, and is in fact so popular down under that he's got his own postage stamp. Seriously.

More recent international gigs haven't gone too well for Hiddink, however. He was sacked as Netherlands gaffer in June after winning just four games from ten and effectively ending Oranje's hopes of qualifying for Euro 2016. His tactics were particularly criticised as outdated.

But no question, the former Fenerbahce, Valencia, Real Madrid, South Korea, PSV, Russia, Turkey and Anzhi boss - to name but a few - is a safe pair of hands. He's not the ultimate answer for Chelsea but can certainly do a job until longer-term candidates become available.

CARLO ANCELOTTI

Carlo Ancelotti

Another former manager Chelsea fans are already well acquainted with. Carlo Ancelotti guided the west Londoners to their third Premier League title in 2010 and did so in rather incredible fashion, the Blues setting a new record of 103 league goals that's still intact today.

He survived just twelve more months, however, rather harshly sacked by Roman Abramovich after finishing second in the league - albeit nine points behind eventual winners Manchester United.

But the Italian is unquestionably one of the best in the business when it comes to handling big players, big clubs and the big pressures accompanying them. In addition to his Premier League title with Chelsea, Ancelotti claimed two Champions League titles and a Serie A title with AC Milan, a Ligue 1 title with PSG and another Champions League title with Real Madrid. He's actually the record holder for European titles along with Liverpool's Bob Paisley.

The 56 year-old is ready for a new challenge after being sacked, rather harshly once again, by Real Madrid during the summer. But according to The Telegraph, he would only be interested in a long-term appointment.

ANTONIO CONTE

Conte

As a player, Antonio Conte won every trophy going during his 13 years with Juventus and almost repeated the feat again as their manager, guiding them to three consecutive Serie A titles but inevitably coming up short in the Coppa Italia and the Champions League.

Regardless, the 46 year-old more than proved his credentials with the Old Lady, demonstrating great tactical understanding, the ability to bond players and a relentless obsession with winning, something which has earned him comparisons with a certain Jose Mourinho.

That success with Juve earned him the Italy gig after the 2014 World Cup, however, and he has since ensured Azzurri qualification to Euro 2016, winning nine and losing just one of his 14 matches in charge. Overall, it would be incredibly surprising if Conte walked out on the job now, with the tournament less than nine months away.

PEP GUARDIOLA

Manchester City v Bayern Munich - UEFA Champions League Group Stage Matchday Five Group E

Linked with every major job in world football, in no small part due to his incredible success with Barcelona. Pep Guardiola was the mastermind who lead the Catalans to three consecutive La Liga titles and two Champions League titles in three years, implementing the tiki-taka inspired dominance of possession and false nine role that the Catalans and flagship star Lionel Messi are now famous for.

He's now attempting to repeat the trick at Bayer Munich but it hasn't quite paid off just yet, with the Germans crashing out of the Champions League in the semi-finals for two years in a row despite previously winning it under Jupp Henckes. That, in combination with his reluctance to sign a new contract, has shrouded the Spaniard's future at the Allianz Arena in recent doubt.

But Roman Abramovich has appointed attacking managers before and none proved particularly successful. Although Guardiola would insist his distinct philosophy is applicable to most squads if accompanied by his own rather intense brand of man-management, the current Chelsea crop is so geared towards Mourinho's image - almost a direct opposite of the 44 year-old's - that his arrival could require a drastic overall of playing personnel.

Likewise, Guardiola has always insisted upon honouring his contracts as a manager and his current deal doesn't expire until the end of the season.

DIEGO SIMEONE

Diego Simeone

The most comparable manager to Jose Mourinho on this list, Diego Simeone is a likeminded character with a likeminded win-at-any-cost mentality.

Indeed, he's reinvented Atletico Madrid into one of the most formidable defensive sides in Europe, using his charismatic personality to insist upon relentless discipline, organisation and opportunism in the final third.

It's not the most aesthetic of approaches but you can hardly argue with the former Argentina international's results. He's guided the Vincente Calderon outfit to a Europa League title, a Copa del Rey and the first non-El-Clasisco La Liga title in a decade since being appointed in 2011 - back when Atletico were on the brink of financial ruin and tenth in the table.

Like Mourinho, the 45 year-old has his own cult-of-personality-style of leadership and cuts a particularly iconic figure, with his dark suit and slick-back hair. He'd sustain the current Chelsea philosophy rather than trying to invent a new one, but is more of the same really what the Blues need right now?

Similarly, Simeone signed a five-year contract in March and is ferociously loyal to the Atletico cause - so Chelsea would have to produce a rather incredible offer to convince him to leave.