At a glance, Juventus’s preparations for a season-defining showdown with Atlético Madrid appear almost ideal. After losing 2-0 at the Wanda Metropolitano, Massimiliano Allegri tweeted that his team had 20 days to “GET READY for a [return leg] TO LIVE and TO WIN”. Since then, the Bianconeri have won three games out of three.

They have triumphed away to Napoli, and since extended their lead atop Serie A to 18 points. On Friday, Juventus beat Udinese 4-1. Repeat that scoreline on Tuesday and they will go through to the quarter-finals.

And yet, none of it has felt as impressive as it looks. That victory in Naples was coloured by a 25th-minute red card for their opponents’ goalkeeper, Alex Meret. Despite having an extra man for almost half the match (before Miralem Pjanic was also sent off), Juventus were largely outplayed.

The side that overran Udinese, meanwhile, will bear scant resemblance to the one that faces Atlético. Cristiano Ronaldo was rested, as were Giorgio Chiellini and Mario Mandzukic. Miralem Pjanic and João Cancelo were suspended. Leonardo Bonucci and Paulo Dybala came off the bench.

Out of 11 starters, only Wojciech Szczesny and Blaise Matuidi can feel certain of retaining their place. The player who impressed most against Udinese might be the least likely to feature in midweek.

Moise Kean scored twice, then won the penalty from which Emre Can made it 3-0. At 19 years old, he was the youngest player to grab a brace for Juventus since Giuseppe Galderisi back in 1982. This, on his first Serie A start of the season.

Kean was thrust into the public consciousness two and a half years ago, when Allegri gave him his debut at 16. He was the first player born in the 2000s to appear in Serie A, and soon the first in a Champions League fixture as well. When he struck against Bologna in May 2017, he became the first player born this millennium to score across any of Europe’s top five leagues.

Moise Kean pounces to beat Juan Musso in the Udinese goal and give Juventus the lead. Photograph: Miguel Medina/AFP/Getty Images

So where has he been hiding? Kean spent last season on loan at Verona: a move that looks ill-judged, with hindsight. Hellas were a disaster, relegated in 19th place, and the expectations placed on a teenager to carry their attack were excessive. Kean notched four goals in 19 appearances before getting injured. That was still enough to finish as the club’s joint-top scorer.

He returned to Juventus knowing competition for places would be fierce, but nevertheless hoping to carve out opportunities. Before Friday, those had been few and far between. Kean’s only two previous appearances in Serie A this season were for a combined three minutes off the bench. His only start was in the Coppa Italia, against Bologna. He scored that day, as well.

Could he yet feature against Atlético, a fresh pair of legs to test an Atlético defence struggling with injuries to Filipe Luís and Diego Godín? The idea was floated on the front cover of Tuttosport on Sunday, but only Allegri can know if it is under serious consideration.

Regardless, Kean’s future will only become a bigger talking point in the weeks ahead. The player’s contract runs until 2020, and he is represented by Mino Raiola. Although Kean has spoken glowingly of the opportunity to train and learn alongside Cristiano Ronaldo, it seems unlikely that he would be eager to continue next season as a reserve.

The speed at which young talent evolves, though, is often hard to predict. When Kean made his debut two seasons ago, he did so in the shadow of another emergent young forward in the city of Turin. Andrea Belotti was, admittedly, no teenager, but not many players could achieve a 26-goal Serie A campaign at the age of 23, either.

At the time, the Torino striker looked destined to establish himself as Italy’s next great No 9. He scored three times in his first two starts for the national team. His progress since, though, has been intermittent. Belotti barely reached double figures in Serie A last term, and he was one of a host of players who failed to live up to billing as the Azzurri crashed out of World Cup qualifying.

Andrea Belotti (bottom right) scores his second goal Torino’s winner against Frosinone to confirm his return to form. Photograph: Federico Proietti/EPA

This season, too, has been a mixed bag. Yet there are recent signs that his confidence might be returning. A week ago, Belotti hit the second-half opener that paved the way for Torino to win 3-0 at home to Chievo. On Sunday, he struck twice as his team reversed a 1-0 deficit to win away to Frosinone. The second was a gem, an artful twisting volley that reminded his teammate Daniele Baselli of the old Panini sticker emblem.

Goals, and victories, over Serie A’s bottom two teams might not sound like much, but Torino are unbeaten now in seven games, winning five of them. That run, which has carried them to sixth in the table, has previously featured wins over Inter and Atalanta, as well as a draw away to Napoli.

The greatest credit goes to the manager, Walter Mazzarri. When Carlo Ancelotti was attempting to illustrate the tactical nuance of Italian football in a recent interview, his mind immediately turned to the way that the Torino manager tweaked his approach between their first and second meetings.

Mazzarri had not transformed his formation but simply adjusted it so that Tomás Rincón would slide out from the centre of a five-man midfield to obstruct the channel through which Piotr Zielinski likes to link up with Lorenzo Insigne. One of Napoli’s preferred angles of attack was taken away.

Torino have often been effective playing the spoiler under Mazzarri. Before Luca Paganini opened the scoring for Frosinone this Sunday, the Granata had gone 599 minutes without conceding a goal in Serie A. What they have struggled with, more often, is making things happen at the other end. Torino’s 35 goals are the fewest of any side in the top half of Serie A.

The club’s president, Urbano Cairo, predicted recently that once Belotti started scoring, the goals would start flowing like coins from a slot machine. A couple more in next week’s game at home to Bologna would set his team up nicely going into the international break.

Talking points to follow