The two clubs experienced very different fortunes in recent UEFA finals, and now they convene in Bergamo, where the Europa League winners will continue to celebrate their breakthrough success.
Match preview
Originally postponed when Fiorentina director Joe Barone suffered a heart attack shortly before kickoff - after which he subsequently passed away - this week's fixture between the Viola and Atalanta has been the source of much debate ever since.
It was ultimately rescheduled for a date when every other Serie A side had packed up and gone on a hard-earned holiday, as both teams' progress in Europe meant that squeezing in any more games elsewhere became all but impossible.
Of course, Atalanta vanquished an apparently invincible Bayer Leverkusen in Dublin, ending a 61-year wait for silverware, and their Europa League triumph also crowned the long career of veteran coach Gian Piero Gasperini.
Ademola Lookman scored a spectacular hat-trick to win a final played just one week after La Dea had succumbed to Juventus in the Coppa Italia decider, and the Nigeria international then struck again in his club's penultimate league game - another 3-0 victory, this time over Torino.
That result means that Gasperini's men can now finish above cup-final conquerors Juve, taking third place in the final Serie A standings behind both Milan clubs; winning this weekend would also make it a 1-2-3 for the region of Lombardy.
Confidence will be high in the Atalanta camp, as they have just won six successive league games for the first time since 2021, and only Italian champions Inter have gleaned more points from home matches this season.
Furthermore, firepower is not a problem: for the first time in club history, the Nerazzurri have seen four players reach double figures in the same Serie A season - Gianluca Scamacca, Teun Koopmeiners (both 12 goals); Lookman and Charles De Ketelaere (both 10).
While their hosts are buoyant, Fiorentina will surely be wishing their campaign had ended at the final whistle on Wednesday, when they endured more final heartbreak in the Europa Conference League's Athens decider.
Summing up the flaws that have seen the Viola consigned to eighth place in Serie A, they were unable to break down a disciplined Olympiacos side in the Greek capital, ultimately losing after extra time.
A year after being beaten in the 2023 edition by West Ham United, in addition to last term's Coppa Italia final loss to Inter, Vincenzo Italiano's side tasted yet another bitter defeat - and now they must face the team that knocked them out in the cup semis this season.
Fiorentina may have won three of their last five league games against Atalanta - after winning only one of the previous 10 - but they let a 1-0 first-leg lead slip on their most recent visit to Bergamo, with La Dea making the most of Nikola Milenkovic's dismissal to turn the tie on its head.
Beating Cagliari 3-2 last week at least means that the Tuscan club have secured a return to the Conference League, where they will try to make it third time lucky next season - incidentally, finishing eighth was only enough to qualify thanks to Atalanta's Europa League victory.
Win, lose or draw on Sunday, Fiorentina are bound to finish between Lazio and Napoli, but as Italiano is expected to say farewell once the dust has settled on another eventful campaign, they will want to send their boss off in some style.
Atalanta BC Serie A form:
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Atalanta BC form (all competitions):
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Fiorentina Serie A form:
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Fiorentina form (all competitions):
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Team News
While Gian Piero Gasperini may be tempted to offer some fringe players a chance in Atalanta's final fixture of a long campaign, third place is still at stake, so stars such as Gianluca Scamacca should start on Sunday.
Since the end of March, no player across Europe's top five leagues has been directly involved in more goals (14) than the Italy striker, who was recently named in Luciano Spalletti's squad for Euro 2024.
Captain Marten De Roon has been ruled out of the Euros due to an injury sustained in La Dea's cup final defeat, and Sead Kolasinac may also miss the season finale with a knee problem; Hans Hateboer must serve a suspension.
Meanwhile, Fiorentina's only absentee will be Riccardo Sottil, who fractured his collarbone earlier this month, as Gaetano Castrovilli is now available after being ineligible for Wednesday's Conference League final.
Sure to make changes after such a setback, Vincenzo Italiano should continue his relentless rotation: the highly-rated coach hardly ever names the same team twice, while only Newcastle and Cagliari have found the net with more different players (18) throughout Europe's top five leagues this term.
Giacomo Bonaventura did not enjoy events in midweek, and was recently overlooked by Spalletti, but he has scored eight league goals in 2023-24 so far - his joint-most in a single Serie A season. Having made his first 99 top-flight appearances for Atalanta between 2008 and 2014, 'Jack' has since scored four times against them, including once in September's reverse fixture - a 3-2 home win for the Viola.
While he competes for selection in midfield, goal-shy strikers Andrea Belotti and M'Bala Nzola battle it out for one berth up front, though Lucas Beltran may be instead moved forward from a supporting role.
Atalanta BC possible starting lineup:
Carnesecchi; Toloi, Djimsiti, Scalvini; Zappacosta, Koopmeiners, Ederson, Ruggeri; De Ketelare, Lookman; Scamacca
Fiorentina possible starting lineup:
Terracciano; Dodo, Milenkovic, Martinez Quarta, Biraghi; Arthur, Bonaventura; Gonzalez, Beltran, Kouame; Nzola
We say: Atalanta BC 2-0 Fiorentina
With more time to rest and recuperate - plus enjoy the party atmosphere throughout Bergamo - Atalanta are sure to end an excellent season in suitable style.