After the teams finished level on points after 38 matches of a gruelling season, they must now fight it out to decide who will retain their top-flight status and who drops down into Serie B.
Following a rule change last year - when Serie A's ruling body decided head-to-head record or goal difference was not sufficient to separate sides that ended level on points and were contesting either the title or survival - a winner-takes-all encounter will determine whether Spezia or Verona stay up.
Sunday's clash in Sassuolo will be the 13th time a relegation playoff has been played in Italy's top flight, with the most recent coming at the conclusion of the 2004-05 campaign, when a two-legged meeting between Emilian rivals Parma and Bologna saw the latter demoted.
The last time two teams faced each other in a one-off finale was back in 1997, but now the fate of both clubs will be decided in a single match played at a neutral venue - the Mapei Stadium, in Reggio Emilia.
Having arrived in Serie A for the first time in 2020 and then defied the drop under both Vincenzo Italiano and Thiago Motta, Spezia stumbled into serious danger this spring, as Leonardo Semplici's side lost 11 of their last 20 fixtures, winning just twice.
While one of those victories came at home to a much-changed Milan, the Aquilotti then took one point from their final three games and finished tied on 31 points with Verona, leaving only Serie B-bound pair Cremonese and Sampdoria below them both in the table.
Like Hellas, Spezia lost their final match, but it was a cruel twist in stoppage time that denied Semplici's men the point they needed to secure sole possession of 17th place. After the unlikely figure of Dimitris Nikolaou had put them in front against Roma at Stadio Olimpico, a late Paulo Dybala penalty consigned the Ligurian club to a 2-1 defeat.
That took their total of goals conceded to 62: the lowest number across their three top-flight seasons to date - and by a margin of nine. However, short of firepower up front and too reliant on top scorer M'bala Nzola, Spezia now find themselves 90 minutes away from the Serie A trapdoor.
After winning three of their first four top-tier meetings with Spezia, in the 2022-23 campaign Verona took just one point from both league fixtures against the Aquilotti. Beaten 2-1 at home in November, Hellas were then held goalless at Stadio Picco in early March, as a more promising start to 2023 faded.
After seeming doomed at the World Cup break, Marco Zaffaroni was brought in as head coach and they rallied; however, that upturn was not maintained and four straight defeats to end the season - including a last-day loss to Milan - saw them dragged into Sunday's demotion decider.
Now playing their part in a relegation playoff for the second time in their history, the Scaligeri secured safety by beating Reggina back in 2001 and will seek to do so again some 22 years later.
That should come as no surprise, as Verona's points haul was their fourth-worst since 1995: on the three previous occasions the Veneto club tallied fewer (in 1996-97, 2015-16 and 2017-18) they were relegated each time.
Having also dropped the most points from winning positions of any Serie A side this term (26), it is perhaps a tale of what might have been for the Gialloblu, who simply cannot afford to let a lead slip on Sunday.
After Kelvin Amian received a late red card and captain Emmanuel Gyasi picked up a booking last week in Rome, Spezia will have to make at least two changes to their starting lineup on Sunday night.
Both must now serve potentially costly suspensions, so Salva Ferrer could make a rare start to cover for Amian's absence on the right flank; either Eldor Shomurodov or Daniele Verde is now likely to partner M'Bala Nzola up front.
Simone Verdi - who scored when these teams met in La Spezia last autumn - Darko Lazovic, Kevin Lasagna and Belgian forward Cyril Ngonge are all contenders to feature in support of the Gialloblu's lone frontman.
Spezia possible starting lineup:
Dragowski; Wisniewski, Ampadu, Nikolaou; Ferrer, Ekdal, Esposito, Bourabia, Reca; Verde, Nzola
Hellas Verona possible starting lineup:
Montipo; Magnani, Hien, Cabal; Faraoni, Tameze, Veloso, Depaoli; Lazovic, Verdi; Djuric
We say: Spezia 1-1 Hellas Verona (Spezia win on penalties)
Only once has a Serie A relegation playoff been decided by a penalty shootout - in 1995, Genoa were demoted on spot-kicks - and in the event of a tie at the end of 90 minutes this Sunday, the game would go straight to penalties without extra time.
Neither team has been sharp enough in the final third this season, so after a low-scoring draw in Sassuolo it could ultimately come down to who holds their nerve from 12 yards.
Our analysis of all available data, including recent performances and player stats up until an hour before kickoff, suggested the most likely outcome of this match was a Spezia win with a probability of 39.69%. A win for Hellas Verona had a probability of 31.92% and a draw had a probability of 28.4%.
The most likely scoreline for a Spezia win was 1-0 with a probability of 12.44%. The next most likely scorelines for that outcome were 2-1 (8.07%) and 2-0 (7.59%). The likeliest Hellas Verona win was 0-1 (10.84%), while for a drawn scoreline it was 1-1 (13.22%). The actual scoreline of 1-3 was predicted with a 2.5% likelihood.