While the Viola let two points slip in Wednesday's draw with Monza, their Emilian counterparts were sunk by lowly Sampdoria.
Match preview
Following an inconsistent start to the season, three wins from four games prior to Italy's long World Cup break saw Fiorentina sneak back into the top of half of the table, and Vincenzo Italiano's side surely planned to start the second phase of their campaign with another in midweek.
All was in hand when Brazilian striker Arthur Cabral's blistering strike gave the Viola a 19th-minute lead, but despite peppering the Monza goal with 22 shots throughout the game, they allowed their visitors to pull level on the hour mark and ultimately had to settle for a point.
Leaving them steadfastly in mid-table, a club set to challenge for continental silverware later this season - they will meet Braga in the Europa Conference League's first knockout round - are some nine points off the pace in terms of booking a European return.
Fiorentina's home form has not helped in that regard, as they have registered two wins, three draws and two defeats from their last seven league fixtures in Florence; scoring just seven times at the Franchi to date.
Therefore, the visit of a side just three points below them in the table - before their third straight home game sees Sampdoria arrive for a Coppa Italia tie next week - is nearing must-win status for Italiano and co.
Struggling for form before the season was halted and Qatar 2022 took centre stage - having picked up just one point from four games, including a 4-0 loss to Napoli and 3-0 defeat at Bologna - Sassuolo's return to competitive action saw their downturn continue.
Despite the passage of almost two months, Alessio Dionisi's men resumed in the same vein, as they soon found themselves two goals behind to a Sampdoria side with just one Serie A win to their name. Despite Domenico Berardi's second-half strike from the spot, they slumped to a 2-1 home defeat.
Like Saturday's hosts, the Neroverdi have struggled for consistency this term, winning just four of their 16 matches to sit closer to the relegation zone than the top eight approaching the season's halfway stage.
Nonetheless, Sassuolo could theoretically leapfrog Fiorentina on goal difference with a substantial victory, and plenty of time remains for Dionisi - who was born in Tuscany and previously coached the Viola's neighbours Empoli - to turn things around.
Berardi's long-awaited return will surely help in that respect, but a record of one win and four goals scored from eight away games to date suggests that the Italy international will need more help from his colleagues up front.
Fiorentina Serie A form:
D
L
W
W
W
L
Fiorentina form (all competitions):
W
W
W
W
W
L
Sassuolo Serie A form:
W
L
L
D
L
L
Sassuolo form (all competitions):
L
L
D
L
L
L
Team News
Ahead of Saturday's game, Fiorentina's injury list features Argentinian forward Nicolas Gonzalez - who is soon set to resume full training - fellow winger Riccardo Sottil and midfielder Rolando Mandragora.
Long-term absentee Gaetano Castrovilli returned to action in midweek from the bench, while Morocco's World Cup hero Sofyan Amrabat is now expected to start after his substitute appearance. A promotion for either would mean young Alessandro Bianco drops out after making his debut on Wednesday; another midfielder, Youssef Maleh, has been loaned to Lecce for the rest of the season.
Up front, Arthur Cabral is set to hold off Luka Jovic's claims for the centre-forward role in Vincenzo Italiano's 4-2-3-1 formation.
Meanwhile, Sassuolo will be without Mert Muldur and Maxime Lopez again this weekend, with Matheus Henrique likely to deputise for the latter once more.
Inter loanee Andrea Pinamonti (three) is trailing behind much-admired midfielder Davide Frattesi (four) in the visitors' modest goal rankings this term, but should still beat off the challenges of Agustin Alvarez and Gregoire Defrel to start up front.
Fiorentina possible starting lineup:
Terracciano; Dodo, Milenkovic, Martinez Quarta, Biraghi; Amrabat, Duncan; Ikone, Barak, Kouame; Cabral
Sassuolo possible starting lineup:
Consigli; Toljan, Tressoldi, Ferrari, Rogerio; Frattesi, Henrique, Thorstvedt; Berardi, Pinamonti, Lauriente