While the Viola bounced straight back from their controversial late loss to Inter last weekend - posting a European win in midweek - their hosts continue to slide down the standings after four defeats in six league games.
Match preview
After Fiorentina battled back from two goals down to draw level at Stadio Artemio Franchi last Saturday, the drama had barely begun, as the home side went behind again before a chaotic conclusion to their meeting with Inter.
Ending a frustrating goal drought - and then celebrating by 'shushing' his own fans - Luka Jovic turned in a last-minute volley to make it 3-3, but there was one more twist in the tale: after Nikola Milenkovic found himself levered off the ball by Edin Dzeko, the visitors' Henrikh Mkhitaryan bundled the ball in for a winner in the fifth minute of stoppage time.
Naturally, there was much dispute in the aftermath, but the result ultimately means that Fiorentina have accrued only 10 points this season and still languish in mid-table.
Following a superb start to his time in the dugout at the Franchi, coach Vincenzo Italiano has now seen his side win just one of their last 10 Serie A matches, and that was at home to lowly Verona.
Events have played out quite differently in Europe, though, as the Viola recently posted back-to-back wins over Hearts in the Europa Conference League before fighting back to defeat Istanbul Basaksehir on Thursday evening, thanks to a Jovic brace.
The Serbian striker's intervention earned progress to the next phase of the competition, and Fiorentina are in contention to top their group. Despite drawing level on points with the Turkish side, they still have an inferior head-to-head record, having lost 3-0 in Istanbul last month.
First place opens up direct access to the last 16; otherwise, a playoff against one of the Europa League drop-outs awaits after the World Cup.
Before next week's final group fixture, Italiano's men must focus on improving their lot domestically. Perhaps a golden chance awaits them in La Spezia, as they have won all three meetings with Sunday's hosts since drawing their first top-flight encounter two years ago.
Italiano returns to the ground he left as a hero - having led Spezia to Italy's top division for the first time and then kept them there - and neither coach since his departure has managed to match his Serie A points average of 1.03 in charge of the Aquilotti.
Following Thiago Motta's mixed spell in Liguria last term, Luca Gotti has seen his new side struggle to compile a consistent run of results and they languish just outside the relegation zone as a result.
Spezia are, alongside Bochum, one of only two teams in the top five European Leagues to have gained all their points at home this season; they are also one of the three Serie A sides still unbeaten in front of their own fans - winning twice and drawing three times so far.
They sit alongside Juventus and Napoli in that regard, and also tasted success in a recent Coppa Italia tie at Stadio Picco, but were beaten again on the road last week, when they succumbed to a 1-0 defeat against Salernitana.
That setback in Salerno saw Spezia become the first Serie A side to lose their first six away games without scoring a single goal since the 1930s. With next week's visit to reigning champions Milan therefore seeming an impossible task, taking points at home this Sunday is all the more important.
Spezia Serie A form:
L
W
L
L
D
L
Spezia form (all competitions):
W
L
L
D
W
L
Fiorentina Serie A form:
L
W
L
L
D
L
Fiorentina form (all competitions):
W
L
W
D
L
W
Team News
While Nicolas Gonzalez may join long-term absentee Gaetano Castrovilli on the sidelines in La Spezia, Vincenzo Italiano's only other injury doubt relates to Riccardo Sottil, who was unable to return in midweek.
Anchoring the visitors' central trio, Sofyan Amrabat scored the most recent of his two Serie A goals at Stadio Picco in February - always combative, the Moroccan midfielder has received the most yellow cards so far in Serie A (six).
Up front, Luka Jovic will expect to retain his place after finally running into some form: however, he last scored in successive league matches in the 2018-19 Bundesliga season.
The Serbian's woes were but nothing relative to Emmanuel Gyasi's struggles for Spezia: among strikers in the top five European leagues yet to either score or assist a single goal this term, the hosts' captain has played the most minutes (900).
Meanwhile, Simone Bastoni and Viktor Kovalenko have both trained separately again as they continue their respective roads to recovery.
In goal, former Fiorentina stopper Bartlomiej Dragowski is the Aquilotti's last line of defence and will seek a first clean sheet since the opening day of the season.
Spezia possible starting lineup:
Dragowski; Ampadu, Kiwior, Nikolaou; Amian, Ekdal, Bourabia, Agudelo, Holm; Gyasi, Nzola
Fiorentina possible starting lineup:
Terracciano; Dodo, Milenkovic, Martinez Quarta, Biraghi; Bonaventura, Amrabat, Mandragora; Ikone, Jovic, Kouame