While the Aquile are top of the recent form table in Serie A, their hosts have won only once in their last seven outings to slip back into relegation trouble.
Joaquin Correa's second successive double strike helped free-scoring Lazio to a seventh win from eight league games last Sunday, as Simone Inzaghi's side now approach a crucial seven days which could define their season.
After Correa's brace against Genoa - in an absorbing 4-3 victory, which Lazio nearly let slip away - followed on from two goals versus Milan in a 3-0 win, the Argentina international and his striker partner Ciro Immobile have undoubtedly re-ignited their respective campaigns. The clinical pair kept the Aquile on course for European football next term by combining to put the Ligurian outfit to the sword at Stadio Olimpico - a venue at which Lazio have now won 11th successive Serie A games.
Though the capital club have been less effective when on the road this term, a total of 14 goals in their last four league outings will have Fiorentina's dubious defence concerned about surviving 90 minutes this Sunday evening.
Such penalty box potency could be integral to overhauling closest clubs Napoli and Milan, as a midweek fixture against doomed Parma follows their trip to Tuscany, before the Derby della Capitale takes centre stage next weekend.
As bitter rivals Roma are currently ailing badly, the Biancocelesti would love nothing better than securing European football at their expense, so must first capitalise on two more straightforward fixtures in the coming days.
Fiorentina prepare for Lazio's visit in the knowledge that, not only have they drifted back into the danger zone of late, but they have also lost five of their last six games against their Roman counterparts.
Furthermore, the Viola have won only one of their seven most recent home games against them in Serie A, so will sorely need star striker Dusan Vlahovic to work his final-third magic once more, having rattled in another pair of goals against Bologna last time out - continuing a breakthrough season for the 21-year-old Serb.
On Sunday, Vlahovic - now on 19 goals this season - could become the first Fiorentina player to score at least 20 times in a single Serie A campaign since legendary frontman Gabriel Batistuta, after his brace helped Beppe Iachini's side to take the lead three times against the Rossoblu, before ultimately settling for a 3-3 draw.
Having seen their back line breached on three occasions by Bologna's veteran forward Rodrigo Palacio - who had previously scored just once all season - Iachini and company have now conceded in each of their last 11 top-flight matches: they have not suffered a longer run without a clean sheet since September 2010.
Given Lazio's white-hot scoring form, then, securing even a point this weekend would provide a significant boost for Fiorentina - who sit just four points above the dotted line - ahead of a potentially critical clash with 17th-placed Cagliari next Wednesday.
While Lazio coach Simone Inzaghi still has three absentees due to injury - Felipe Caicedo (heel), Luiz Felipe (ankle) and Gonzalo Escalante - only wing-back Mohamed Fares has joined them on the sidelines ahead of Saturday's game, as the Algeria international must serve a suspension for yellow card accumulation.
First-choice centre-back Francesco Acerbi returns from a ban though, so will return to the team in place of Wesley Hoedt, while Senad Lulic should continue on the left of Inzaghi's 3-5-2 in the absence of Fares.
The hosts, meanwhile, still have striker Aleksandr Kokorin and veteran midfielder Borja Valero out of action with thigh injuries - with Brazilian defender Igor also missing out through suspension, as a result of picking up a booking as a substitute last week.
French forward Franck Ribery has defied his age to start regularly for Fiorentina in recent weeks and is expected to overcome a minor knee issue to start alongside the now irreplaceable Dusan Vlahovic up front.
In the creative department of Beppe Iachini's side, Gaetano Castrovilli will hope to regain his place in the first XI after losing his way during an unproductive 2021 so far, though Giacomo Bonaventura has featured more regularly of late.
Fiorentina possible starting lineup:
Dragowski; Milenkovic, Pezzella, Caceres; Venuti, Amrabat, Pulgar, Bonaventura, Biraghi; Ribery, Vlahovic
Lazio possible starting lineup:
Reina; Marusic, Acerbi, Radu; Lazzari, Milinkovic-Savic, Leiva, Luis Alberto, Lulic; Correa, Immobile
We say: Fiorentina 1-3 Lazio
Lazio justifiably come into this clash as strong favourites, with their undoubted quality in the final third set to help them brush aside their labouring opponents and secure maximum points on Saturday.
With only young Dusan Vlahovic proving a reliable source of goals this term, Fiorentina are often a lightweight proposition, so the Aquile can power on to an eighth win in nine - as a return to the Champions League remains a live possibility.