Over the last few years, the Blues have collected more than £100m worth of players who are now out on loan - many of whom have never even had the opportunity to pull the shirt on in a Premier League match.
Many of them are young players signed as teenagers for relatively large sums, often running into the millions - and far from hurting Chelsea's finances, they will actually help the club balance their books in the era of UEFA's Financial Fair Play regulations as the loan fees stack up.
On top of that, Chelsea have actually done incredibly well. Romelu Lukaku's years out on loan saw his value soar from the £10m plus add-ons that Chelsea paid for him in 2011 to the £28m Everton laid out this summer. And all the while, his wages were paid by the clubs who enjoyed his services on loan.
Sometimes, the gamble pays off even more handsomely. The Blues paid Genk a reported (though unconfirmed) fee of around £5m for Thibaut Courtois three years ago - and after watching him prove himself one of the world's finest in a Liga-winning Atletico Madrid side, they were able to recall him this summer. That effectively gave them a superb goalkeeper for less than a quarter of his current estimated market value.
Not everyone works out that way. Gael Kakuta, Chelsea's unofficial 'king of the loanees', is just 23 years old but has been at Stamford Bridge since 2007. Since then he has played for Fulham, Bolton, Dijon, Vitesse, Lazio and now Rayo Vallecano; he has six senior Chelsea appearances to his name, but seems destined never to play for the side again.
Many have claimed that Kakuta could have been a superb talent had he not wasted his best years on loan. Michael Ballack said of him "he is the star" after playing alongside him for the Blues, while Chelsea scout Guy Hillion once said that, "it is a huge waste… He is the most gifted player of his generation. He could have been exceptional."
Here's our pick for a best Chelsea XI of players currently out on loan, a line-up which contains Champions League winners and international stars... and which would probably stand a fighting chance in any top flight across Europe:
Chelsea's on-loan XI
Chelsea's on-loan stars - the full list:
Bertrand Traore (Vitesse Arnhem)
Christian Atsu (Everton)
Cristian Cuevas (Universidad de Chile)
Gael Kakuta (Rayo Vallecano)
Islam Feruz (OFI Crete)
Jamal Blackman (Middlesbrough)
Joao Rodriguez (Bastia)
John Swift (Rotherham)
Josh McEachran (Vitesse Arnhem)
Kenneth Omeruo (Middlesbrough)
Lucas Piazon (Frankfurt)
Mario Pasalic (Elche)
Marko Marin (Fiorentina)
Marko van Ginkel (AC Milan)
Matej Delac (Arles-Avignon)
Nathaniel Chalobah (Burnley)
Oriol Romeu (Stuttgart)
Patrick Bamford (Middlesbrough)
Ryan Bertrand (Southampton)
Stipe Perica (NAC)
Tomas Kalas (Cologne)
Thorgan Hazard (Borussia M'gladbach)
Ulises Davila (Tenerife)
Wallace (Vitesse Arnhem)
- Sports & Recreation
- Gael Kakuta
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