Chelsea fans certainly have a lot to thank billionaire owner Roman Abramovich for.

The Blues had long been a piece of the furniture amongst English football's elite, but a changing of the guard in their boardroom brought about an instant uplift in their Premier League displays.

Winning the 2004-05 title with just a single defeat and the greatest defensive record in the competition's history was an emphatic way to end a 50-wait for a league crown.

Since then, the west London side have added a further four Premier League trophies to their cabinet and Abramovich's endless financial resources have played a massive role in each of them.

Players like Didier Drogba, Cesc Fabregas, Claude Makelele and Ricardo Carvalho are just a handful of examples where the Russian's millions have brought strength to the Chelsea XI.

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Worst XI of Chelsea signings

But especially amongst the constant managerial merry-go-round at the club, it's guaranteed that a few mega-money signings fall short of expectations.

Chelsea fans could count on both hands a number of purchases who have failed to meet the hype and talkSPORT have taken a unique look at some of Abramovich's most ill-fated buys.

They've drawn up an XI of the worst players that Chelsea have bought since 2003 and with nearly two decades of clunkers to sift through, it makes for very interesting reading - check it out below:

Goalkeeper: Kepa Arrizabalaga

Give or take a meltdown in the League Cup final, Arrizabalaga was actually pretty impressive in his debut season with the Blues, but how things have changed.

A number of high-profile errors and distinct lack of clean-sheets saw Frank Lampard drop him for 38-year-old Willy Caballero and he's rumoured to have been dumped on the club's transfer list. 

Right-back: Khalid Boulahrouz

Arguably the most random player to ever wear Chelsea's number nine jersey, the 'Cannibal' wasn't as suited to the Premier League as his nickname suggests.

The £8.5 million-signing quickly found himself on the bench after a series of poor performances and was dumped at Stuttgart just two years later for barely half the fee they paid for him.

Centre-back: Tal Ben Haim

Astonishingly, Ben Haim was initially a starter for Mourinho after injuries to John Terry and Carvalho, but the arrival of Avram Grant slammed the brakes on his Chelsea career despite their mutual nationality.

The Israeli seemed to tour England upon being ejected from the Bridge after a solitary season, playing for QPR, Charlton Athletic, West Ham and Manchester City and Portsmouth.

Centre-back: Papy Djilobodji

Played one minute for the club... and it came in a League Cup game against Walsall... what more can we say?

The Senegalese international was swiftly dumped to Sunderland, who then sacked him for alleged breaches of his contract and failing to pass a fitness test. Charming.

Left-back: Asier Del Horno

Arriving for £8 million and lasting just a single season sums up a dire spell in England for Del Horno whose most famous contribution at the club was being sent off for hacking down Lionel Messi.

That first-half dismissal proved pivotal in Chelsea losing the tie to Barcelona and ultimately crashing out of the Champions League.

Midfield: Maniche

Not everybody that Mourinho brought to England from his Champions League-winning Porto side was a success and Maniche is the perfect example, registering just eight league appearances.

His first start for the club was an absolute nightmare, too - smashing the crossbar to miss an easy chance from barely six yards and then picking up a red card in the 17th minute.

Midfield: Juan Sebastian Veron

Just as they did with Radamel Falcao 10 years later, Chelsea brought in a world-class player from Manchester United who'd flopped in England in the hope that a change of scenery would help.

Spolier alert: It didn't. Despite scoring at Anfield on his debut, Veron was kicked out the exit after just 14 appearances and was sent out on loan to Inter Milan and Estudiantes.

Midfield: Steve Sidwell

Bafflingly unveiled by Mourinho with the number nine shirt and as apparent competition for Frank Lampard and Michael Essien, Sidwell was never cut out for success at Stamford Bridge.

Arguably the most bizarre signing in Chelsea's recent history was shuffled along to Aston Villa after a single season and with just a token goal in blue to his name.

Forward: Fernando Torres

Chelsea seemed to be the only club in the world who didn't realise Torres was on the way down when they splashed out a then English record of £50 million on January Deadline Day, 2011.

Taking three months to score his first goal for the club and only ever notching 20 league strikes in 110 outings quickly changed the narrative, though, prompting them to sell up in 2014.

Forward: Andriy Shevchenko

Chelsea spent many a year chasing Ballon d'Or winner Shevchenko, but it was the player himself who looked spent by the time Mourinho got his hands on him in 2006.

Just nine goals in 48 Premier League games represented a dire record from a very expensive purchase at the time at £30.8 million, eventually culminating in a loan return to AC Milan.

Forward: Ricardo Quaresma

Anybody who's ever seen Quaresma play knows he has bags of talent, it just depends on whether he can bothered to prove it and there was little evidence of his class in the Premier League.

Just four games and zero goals show exactly why Mourinho chucked him out on loan in the first place, mere months after being named the worst player in Serie A.

Wasted money

On paper, certain areas of this team look pretty strong, but their performances at Stamford Bridge told us otherwise.

Players like Quaresma, Shevchenko and Veron are fine examples of world-class players who proved themselves on the continent, only to struggle under the rigours of English football.

Then there's Sidwell and Djilobodji who, to put things mildly, should never have been signed in the first place.

But when Abramovich has enough money to buy himself a super yacht with an anti-missile defence system, we're sure he won't lose too much sleep about the odd £10 million signing failing to deliver.