Italian football’s summer break began in much the same way as the season had ended: with Juventus way out in front. By 1 July they had concluded the free agent signings of Aaron Ramsey and Adrien Rabiot. Then they did something far more audacious: signing Matthijs de Ligt from Ajax for €75m.

Even for a club that signed Cristiano Ronaldo one year previously, it felt like a landmark deal. When did an Italian side last win a bidding war for one of European football’s most coveted young talents? At 19 years old, De Ligt had already started in a Champions League semi-final, a Europa League final and a Nations League final – not to mention winning a domestic double in the Netherlands. The centre-back was expected to land in Barcelona, Madrid, Munich or Paris. Instead, he came to Turin.

As De Ligt put pen to paper, the gap between Juventus and their domestic rivals looked as wide as it has at any point during this eight-year stretch of consecutive Serie A titles. A team that finished 11 points clear of second place last season, and 21 ahead of third, had strengthened even further. How was anyone supposed to keep up?

Five weeks later, however, the picture does not look so clear. Such additions were supposed to be offset by subtractions. Two days out from the start of the season, too few sales have been completed, leaving the new manager, Maurizio Sarri, with a bloated and unwieldy playing squad.

“We need to cut six players from our Champions League list – and that puts us in difficulty,” he acknowledged this month. “It’s an embarrassing and difficult situation. We risk having to leave some really high-level players off the list.”

Ramsey and Rabiot join a midfield group in which Miralem Pjanic, Emre Can, Blaise Matuidi, Rodrigo Bentancur and Sami Khedira were already competing for places. Khedira, at least, was presumed to be on his way out after a lacklustre 2018-19 campaign, but insisted in an interview with Kicker this week that he intends to stay put.

Up front, Ronaldo’s potential supporting cast includes Paulo Dybala, Gonzalo Higuaín, Mario Mandzukic, Douglas Costa, Federico Bernardeschi and Juan Cuadrado. Sarri’s efforts to build something coherent from that group has been complicated by not knowing which will still be available to him beyond the end of this month.

Pre-season friendlies should always be taken with a pinch of salt, but performances have not been impressive. Preparations were disrupted further after Sarri contracted pneumonia. Juventus have said he will not be well enough to sit on the bench for the season opener against Parma or the second match against Napoli.

It is easy to imagine a scenario in which fans might turn on Sarri if Juventus were to drop points early. The club’s decision to hand the reins to a former rival, who had never won a major trophy before his Europa League triumph at Chelsea this May, was unpopular with many from the start.

There are reasons to believe that the competition will be stiffer in Serie A this season as well. The manager who launched Juventus’s winning cycle has returned to the peninsula on a mission to end it. Antonio Conte told GQ Italia that he would not have accepted the Internazionale job unless he believed there was at least a chance to depose his former club as champions.

Antonio Conte has been pleased with his summer recruitment at Inter though may have to reintegrate Mauro Icardi. Photograph: Glyn Kirk/AFP/Getty Images

His top transfer targets have been delivered. Not everyone is sold on Inter’s recruitment of Romelu Lukaku – and potentially Alexis Sánchez – to lead the line, but Conte has wanted to work with the Belgian ever since he was in charge of Juventus. Nicolò Barella and Stefano Sensi will bring a much-needed injection of dynamism to midfield and Diego Godín can provide leadership to an already sturdy defence.

The enduring presence of Mauro Icardi, however, gives Inter an unwanted distraction of their own. The striker has been told in no uncertain terms that he is not part of the club’s plans, yet if no buyer can be found in the next fortnight Conte may have to reintegrate him.

Napoli had presented themselves as potential suitors for Icardi, but are expected to abandon their interest unless he offers them some encouragement soon. Regardless, the Partenopei might be a greater threat than Inter to Juventus retaining the Scudetto.

The addition of Kostas Manolas, to play alongside Kalidou Koulibaly, means that last year’s runners-up boast the best centre-back tandem in the division. Behind them, it is reasonable to expect the 22-year-old goalkeeper Alex Meret to continue his improvement. The team that concede the fewest goals have finished top of Serie A in each of the past 12 seasons.

Napoli will have more options going forward, too, with the arrival of Hirving Lozano. And although Carlo Ancelotti has not won a Scudetto as recently as Conte, he knows a thing or two about what is required. “Second place is not enough any more,” he told reporters recently. “Now we need to win something.”

It is hard to imagine Atalanta, with their more modest resources, crashing the title race, but they may not be easily dislodged from the top four. Gianluca Mancini’s sale to Roma has been their only major departure, while Luis Muriel offers a different option up front.

The Giallorossi themselves will be fascinating to watch under Paulo Fonseca, whose high press and vertical approach served him so well at Shakhtar Donetsk. Pau López can only be an upgrade over Robin Olsen in goal, and Edin Dzeko surprised many by deciding to sign a new contract after all.

Milan also have a new manager, Marco Giampaolo, as well as a refreshed squad. It might seem odd to cite the arrival of two players from relegated Empoli as a cause for optimism, but Rade Krunic scored five goals and set up seven more from central midfield last season. Ismaël Bennacer was named player of the tournament at this summer’s Africa Cup of Nations.

Mario Balotelli hopes his return to Italy, with Brescia, will reignite his international career. Photograph: Filippo Venezia/EPA

Lazio have had a quieter transfer window, though Manuel Lazzari is a quality addition on the right. Torino, largely unchanged from last season, landed a tough draw against Wolves in their Europa League qualifier, but may yet surprise if they can make an asset of their continuity.

There are plenty of fascinating subplots to keep an eye on, as Franck Ribéry teams up with Kevin-Prince Boateng at Fiorentina, Radja Nainggolan returns to Cagliari and Mario Balotelli comes back to Serie A. The striker told reporters that his mother started crying when he told her that he was signing for Brescia – his hometown club.

Balotelli hopes the move will help him win back a place in the Italy team before the 2020 European Championship. First, though, he will have to find his place in a side that already boasts a prolific No 9, Alfredo Donnarumma (no relation to Gianluigi), who scored 25 goals last season to fire the team to promotion.

If Balotelli succeeds, it could become one of the great romantic stories in European football this season. If not, then it may all end, as it started, in tears.