Ranieri was sacked after just 106 days in charge, winning only three of 17 games during that spell. The Premier League title winner was brought in to galvanise Fulham and guide them to safety, but he leaves them in a worse position than they were in when he arrived a little under four months ago.
In many ways Ranieri's tenure came full circle with Wednesday's 2-0 loss at Southampton, having picked up a 3-2 victory over the same side in his first match in charge. Eleven defeats would follow, though, including an FA Cup third-round exit at home to fourth tier Oldham Athletic, and now Scott Parker has been promoted from his previous role as first-team coach.
Parker has the chance to make the job his own, but for that to happen he needs to see an instant response from his players. The Cottagers, without a point in their last four matches, face Chelsea, Liverpool and Manchester City in three of their next four games.
Going further back, it is seven defeats in eight Premier League outings for Fulham, conceding at least twice in all eight matches. No team has a worse defensive record in the top flight, shipping 63 goals in total.
Fulham have conceded more goals in both the first half (32) and second half (31) of Premier League matches this season than Chelsea have in total (29), and they have struggled at the other end of the field, too, scoring just once during their four-match losing streak - Ryan Babel's early opener at West Ham United, which was cancelled out by three goals from the Hammers.
More recently than that, the Cottagers offered very little as they suffered defeat in what was billed a must-win match at Southampton. Both goals came as a result of poor goalkeeping from Sergio Rico, and only when two down did they offer any sort of response at St Mary's Stadium - even that was after their opponents had backed off, happy to soak up the pressure.
The gap on Southampton in 17th place is now 10 points and, with just 10 more games to play, the Cottagers' fate will surely be confirmed before the end of next month. All Parker can ask for is a response of some sort from Fulham's underperforming players, starting with Sunday's meeting with neighbours Chelsea.
Recent form in Premier League: LWLLLL
Sarri could not be certain that he would still be in charge for the midweek meeting with Tottenham, but he was given a stay of execution by his bosses and will continue take each game as it comes.
Chelsea produced an improved display in the penalty-shootout loss to Man City at Wembley, certainly in comparison to the 6-0 thrashing against the same side a couple of weeks prior, and they were deserved winners against Spurs.
That win over their London rivals ensures that the Blues' top-four hopes remains in their hands, as they trail Manchester United by two points and fourth-placed Arsenal by three, though they have a game in hand - against Brighton & Hove Albion - to pencil in.
With United and Arsenal enjoying a good run of form over the past couple of months, the pressure is on Chelsea to keep pace. After losing three games out of four heading into the Tottenham match, Sarri knew that only three points would suffice.
The blow of tasting defeat in both domestic cup competitions in the space of a week has been softened slightly by their advancement in the Europa League, with Dynamo Kiev up next for a place in the quarter-finals, and qualifying for the Champions League - no matter how they achieve it - will likely determine whether Sarri is given a second season at Stamford Bridge.
Sarri has improved his side in a defensive sense following 4-0 and 6-0 defeats to Bournemouth and Man City respectively, keeping out the Citizens in their latest tussle, as well as recording shutouts against Malmo and Tottenham either side. They are now seeking a fourth consecutive clean sheet in all competitions for the first time since December 2016.
Chelsea have lost two of their four away London derbies this season, though, and have not lost three in a single season since 2001-02. However, Fulham have lost all nine such fixtures this term and could become the first team in top-flight history to lose 10 in a single campaign.
With his future still up in the air, Sarri could not have picked a better opponent to play. Any slip-ups between now and the end of the season will lead to calls for the Italian to leave, but a favourable fixture list over the next seven weeks gives the ex-Napoli boss a chance to finally rebuild some momentum.
Recent form in Premier League: WLLWLW
Recent form (all competitions): LWLWLW
Sarri indicated after the midweek win over Tottenham that Kepa Arrizabalaga, despite his EFL Cup final theatrics when refusing to leave the field, remains Chelsea's number-one goalkeeper and will be "back in the team for the weekend".
There are expected to be further changes elsewhere, too, with Emerson Palmieri in contention to fill in for Marcos Alonso and Ross Barkley the obvious choice to replace Mateo Kovacic in central midfield.
Eden Hazard looked fatigued last time out and, with five games to play between now and the international break in three weeks' time, this is surely the right time to recall Callum Hudson-Odoi and give the Belgian a breather.
Pedro may also make way from the Tottenham win, though Sarri will be aware of the Spaniard's record in London derbies - half of his Premier League goals this season have come against teams from the capital.
Ranieri made a big call for what turned out to be his final match in charge by recalling Kevin McDonald and Andre-Frank Zambo Anguissa in midfield, which led to Tom Cairney being fielded out of position in the frontline.
Former Chelsea midfielder Parker will no doubt make changes to put his stamp on things, and that could include a recall for fan favourite Ryan Sessegnon and a change of formation.
Fulham possible starting lineup:
Rico; Odoi, Nordtveit, Ream, Bryan; Cairney, Chambers, Seri, Sessegnon; Babel; Mitrovic
Chelsea possible starting lineup:
Kepa; Emerson, Rudiger, Luiz, Azpilicueta; Kante, Jorginho, Barkley; Hudson-Odoi, Higuain, Willian
Head To Head
Fulham have won just one of their last 32 Premier League meetings with Chelsea, beating them 1-0 in the top flight 13 years ago this month.
The Blues are unbeaten in their last 17 Prem games against their West London rivals, winning 10 and drawing seven of those. Only against Tottenham (28) and Everton (18) have they had longer unbeaten runs in the competition.
We say: Fulham 0-3 Chelsea
Chelsea will hope that they have turned a corner following their positive displays against Man City and Tottenham. The Blues cannot afford to drop points if they are to keep pace with the two sides directly above them, and that is unlikely to happen this weekend as they come up against a doomed Fulham side.