It's all on the line as Serie A's top four race goes to the wire

With one game of the Serie A season to go, the formula could not be simpler: one of Italy's biggest sides will miss out on Champions League football next season.

With Inter Milan preparing for their Scudetto title party this Sunday and attacking outfit Atalanta already safe in the top four battle, just one point separates AC Milan, Napoli and Juventus in the race for the final two spots.

Failure to qualify for Europe's premier club competition could have huge ramifications for any of the three managers in charge. Milan head coach Stefano Pioli has been walking a tightrope since the Rossoneri's drop from the summit, while former team-mates Andrea Pirlo and Gennaro Gattuso could stab the other in the back.

Another potential outcome is that one of Cristiano Ronaldo and Zlatan Ibrahimovic, both legends on Europe's biggest stage, will miss out on appearing in the Champions League next season.

With Sunday night's Serie A action set to be packed full of drama and suspense, Sportsmail goes through the lie of the land ahead of the season climax...

COULD PIRLO'S REBUILD END BEFORE IT'S EVEN BEGUN?

The unthinkable could happen. Juventus - winners of the last nine Serie A titles and led by Ronaldo - could miss out on Champions League football altogether.

The Old Lady go into the season finale with their top four hopes out of their hands. Juventus need to beat Bologna away from home and hope one of Milan or Napoli drop points in the corresponding matches.

Playing in the Europa League could have major ramifications for Juventus' plans for next season. Would that be enough to keep Ronaldo? Gianluigi Buffon has already revealed his desire to quit at the end of the season, but could fellow stalwart Giorgio Chiellini join him in the exodus?

Head coach Pirlo has put a lot of faith in the likes of Aaron Ramsey and Alvaro Morata this season but failure to reach the Champions League could put their futures in doubt this season. And what about loanee Weston McKennie and the ever-reliable Paulo Dybala should they finish fifth?

Juventus hired the inexperienced Pirlo to begin a rebuild following the sacking of Scudetto winner Maurizio Sarri - but the Old Lady chiefs could not have foreseen such a fall from grace in the domestic game.

The Italian is not expected to be kept on next season should his side end up in the Europa League, meaning Juve would be starting from scratch once again in the search of a new manager - who will surely face an exodus of first-team stars.

What will also hurt is the sight of Antonio Conte - who started Juventus' Italian dominance a decade ago - lifting the Serie A title with arch-rivals Inter Milan.

The Old Lady's win over Atalanta in Wednesday's Coppa Italia final shows that Pirlo can guide his side to success when the pressure is on.

Top four would give them some hope of continuing Pirlo's journey - or could it act as a stepping stone for a more experienced manager to come in and bring success back to Turin? Either way, Pirlo can't sit comfortably yet.

GATTUSO LOOKING TO PUT ONE OVER OLD PAL PIRLO

Football is a funny game isn't it? Last February, Napoli took on Juventus knowing that defeat for the Partenopei would see head coach Gennaro Gattuso sacked from his role.

Fast forward three months and Gattuso not only remains in charge but has Napoli in pole position to reach next season's Champions League - at the possible expense of his former AC Milan and international team-mate Pirlo.

The Italian managed to keep his job by beating Juventus 1-0 that day, which showed Napoli could still compete with the big boys.

Gattuso's side have since won away at AC Milan and Roma in their push for the top four and and they go into the final fixture unbeaten in their last eight games.

The return of Victor Osimhen from injury has been pivotal to Napoli's recent revival under Gattuso. The 22-year-old not only mustered eight goals in 11 league games in a flurry starting from the beginning of March, but has re-established the epic front three of him, Lorenzo Insigne and Hirving Lozano that dazzled at the start of the campaign.

Add that to Dries Mertens and Matteo Politano and Gattuso's Napoli have been one of the free-scoring Serie A sides in recent weeks. The Partenopei have picked up victories over Udinese and Lazio by scoring five goals, while a 4-3 win over Crotone was deemed to be one of the turning points in Napoli's season.

Napoli's task is simple: beat mid-table Verona - who have not won in eight matches and have a top-half finish fairly secure - and they will have Champions League football next season.

A place in the top four is not yet guaranteed for Napoli, but there's a reason why Gattuso's men are favourites for a top four spot...

COULD THIS BE THE BOTTLE OF ALL BOTTLES FROM AC MILAN?

At the start of February, AC Milan sat top of the table having been there all season. With Zlatan Ibrahimovic returning from injury, the Rossoneri looked on course for a first league title in a decade.

But Stefano Pioli's side have dropped points eight times since then to leave them with a very serious chance of ending the campaign in fifth position.

Consistency has been a rarity in the red half of the San Siro in recent weeks. Victories away at Juventus, Roma and Fiorentina have come alongside crushing losses to Lazio, Napoli, Spezia and Sassuolo.

Not even an emphatic 7-0 away victory at Torino last week could help secure their Champions League status for next season - the first time they would have reached Europe's elite club tournament since the 2013-14 campaign.

Out of all of the top four rivals competing for the two spots this Sunday, Milan have the hardest fixture. A trip to second-placed Atalanta is by no means a routine victory given that Gian Piero Gasperini's side have netted over 100 goals once again this season.

Despite already qualifying for the Champions League, Atalanta will by no means treat Sunday's encounter as a dead rubber. The city of Bergamo is often condescendingly treated as the 'suburbs of Milan' so there is local pride at stake.

Finishing fifth would be damning for head coach Pioli, who looked set to be taking Milan on a historic season this term.

Their form towards the back end of last season controversially kept Pioli in a job, despite the imminent arrival of Ralf Rangnick. But this season's finale could spell the end for the Italian.