The Viola have picked up just three points so far, while their counterparts from the capital are faring much better following last week's win over Hellas Verona.
Match preview
After ending up empty-handed against Atalanta BC last weekend - when they lost 3-2 in Bergamo, with all five goals coming in a frantic first half - Fiorentina have failed to win any of their first four Serie A fixtures for the first time since 2019.
Lucas Martinez Quarta and then Moise Kean twice put the Tuscan side in front versus La Dea, but they were twice pegged back before Ademola Lookman scored what transpired to be the winning goal during first-half stoppage time.
Only three times in their long top-flight history have Fiorentina failed to win any of their first five matches - and the last occasion was nearly five decades ago - but that fate awaits Raffaele Palladino's men if they cannot get off the mark this weekend.
Occupying 14th place in the early Serie A standings, the Viola's only success so far this season came via a penalty shootout in last month's Conference League playoffs, after two draws with Puskas Akademia sent the tie down to spot kicks.
Now, they will hope to build on an improving record against Lazio, who they beat 2-1 at the Franchi in February: Fiorentina have picked up four points from their last three meetings with Sunday's visitors - as many as from the previous 10.
Even though they were defeated on their last visit to Tuscany, Lazio have lost only two of their last 14 matches against Fiorentina in Serie A, winning no fewer than nine.
They will approach this week's clash on the back of their second success of the season, after goals from Boulaye Dia and Taty Castellanos secured a 2-1 home victory over Verona on Monday evening.
New Biancocelesti boss Marco Baroni could celebrate success against his old club, and he now returns to his hometown of Florence seeking three more points to bolster Lazio's total of seven so far.
Ahead of his team's first European fixture - Dynamo Kiev are their opening Europa League opponents next week - Baroni will be intent on maintaining his current club's impressive form either side of the summer break.
Lazio have lost just one of their last 11 Serie A matches, averaging two points per game in the process, and during that time only Atalanta have performed better.
Fiorentina Serie A form:
Fiorentina form (all competitions):
D
D
D
W
D
L
Lazio Serie A form:
Team News
Set to make Fiorentina's matchday squad for the first time since signing from Genoa in the summer, Icelandic striker Albert Gudmundsson could be included as a substitute after finally overcoming a calf injury.
David de Gea made his first Serie A start last week and could continue to keep Pietro Terracciano on the bench, featuring behind a back three led by Lucas Martinez Quarta.
Following his strike in Bergamo, Martinez Quarta has scored six league goals since the start of 2023-24 - no defender has recorded more throughout the Italian top flight - and he is also the only centre-back to have scored in each of the last five seasons.
Meanwhile, Lazio's sole concern relates to Argentinian striker Taty Castellanos, who limped out of Monday's game with a muscular injury.
The ex-Girona forward has since resumed training but may not be risked, meaning Boulaye Dia would most likely lead the line up front. Between them, the pair have been responsible for five of the Biancocelesti's eight goals this season.
Whoever starts at centre-forward will be supported by captain Mattia Zaccagni and any one of Gustav Isaksen, Tijjani Noslin or Loum Tchaouna.
Fiorentina possible starting lineup:
De Gea; Martinez Quarta, Pongracic, Biraghi; Dodo, Cataldi, Mandragora, Gosens; Sottil, Colpani; Kean
Lazio possible starting lineup:
Provedel; Lazzari, Gila, Romagnoli, Tavares; Dele-Bashiru, Rovella, Guendouzi; Isaksen, Dia, Zaccagni
We say: Fiorentina 2-2 Lazio
Fiorentina will have to wait for their first win, as Lazio have started the season well and are more than capable of breaching their hosts' defence.