Astonishingly, Thomas Tuchel is no longer Chelsea's head coach after being relieved of his duties in the wake of the 1-0 defeat to Dinamo Zagreb in the Champions League.
The German had just overseen a world record £273m spend in the summer transfer window, but Todd Boehly and the Chelsea board have opted to axe Tuchel after an indifferent start to the season - one that has seen the club struggle to forge any kind of identity on the pitch and one that has looked toothless in front of goal.
The search will now begin for Tuchel's replacement, with Chelsea looking to make a swift appointment, but who will be in the frame to replace him?
Clubs managed: Ostersund, Swansea, Brighton
Brighton are continuing to go from strength to strength under Graham Potter and it's no surprise to see him touted as one of the favourites to take over.
The Seagulls will do their utmost to keep hold of Potter, should an approach be made, and there's no guarantee that the 47-year-old would walk away from a hugely appealing project down on the south coast.
But his stock has risen exponentially over the last 12 months, and he's widely regarded as one of the most progressive coaches in the game.
Clubs managed: Espanyol, Southampton, Tottenham, Paris Saint-Germain
Tottenham Hotspur fans, look away now.
It would seem unlikely that Mauricio Pochettino would break his bond with the club's supporters but could he really turn down the advances of Chelsea if they came calling? He has an abundance of Premier League experience, with Southampton as well as Spurs, and has a proven track record of getting the best out of players.
Failing to win the Champions League with PSG has tarnished Pochettino's reputation a little, but he remains one of the best coaches in the world.
Clubs managed: Braga B, Braga, Sporting CP
A young Portuguese manager who has already won his domestic title and is already recognised as one of the game's brightest coaches - sound familiar Chelsea fans?
Ruben Amorim certainly is no Jose Mourinho, but he is an exciting coach who has attracted plenty of admirers for the work he's done at Sporting CP. His opportunity in Lisbon came after a short, bright spell at Braga, whom he lifted the Taca de Liga with (Portugal's domestic cup competition).
Back-to-back successes in that competition have followed with Sporting, while he also ended the club's 19-year wait for a 23rd Primeira Liga title during 2020/21. Amorim's side have been no pushovers in Europe either, and there should be no ruling out of a sudden switch to England.
Clubs managed: Real Madrid Castilla, Real Madrid
Zinedine Zidane's name is in the mix for every big job going and Chelsea's vacancy is bound to be one the Frenchman is linked to.
Two hugely successful spells at Real Madrid make Zidane an enticing prospect for Todd Boehly and the Blues board - given his reputation and status in the game - but it remains to be seen whether he can be talked out of waiting for the France job, which may become available after this winter's World Cup.
A proven winner in the big leagues, Zidane's pedigree could be just what Chelsea need to get back on top, but style wise he's not necessarily the right fit.
Clubs managed: Fiorentina, Lazio, Inter, Manchester City, Galatasaray, Zenit
One manager who has been out of the club scene for a little while is Roberto Mancini, but the Italy boss could be swayed by the prospect of taking over at Stamford Bridge.
He's won the European Championship with his country but wasn't able to qualify for this winter's World Cup in Qatar, meaning there's very little for him to achieve on the international stage - unless he wants to have another crack at the Euros.
A Premier League winner with Manchester City, Mancini knows how to get it done in England and is used to the pressure of managing a top club.
Clubs managed: Watford, Reading, Swansea, Liverpool, Celtic, Leicester
Leicester City are in the doldrums right now, sitting plum bottom of the Premier League table, but Brendan Rodgers' reputation remains in tact.
The Northern Irishman also cut his teeth at Chelsea, honing his skills as a coach at youth level, and the opportunity to return to Stamford Bridge could bring to an end a three-year spell at King Power which has stalled somewhat after finishes in the Premier League's top six and a first-ever FA Cup win.
Rodgers would also reunite with Wesley Fofana, having plucked him out of relative obscurity to help coach him into being one of Europe's top defenders.