When Max Allegri returned to Juventus in the summer, everyone in Turin expected his arrival would coincide with an immediate return to the winning ways of his first trophy-laden period in charge of the club.

His return was essentially an admission the club had wasted the two years since he left. The hope from the boardroom was that he would reinvigorate a club whose vice-like grip on the Serie A title was finally ended last season after nine straight league triumphs.

But so far there has been no fairytale comeback.

A week ago, Juve were in the relegation zone, winless after four games and facing a match against Spezia which Allegri described as a “relegation six pointer”.

Seven days and back-to-back victories later, Juve are at least in the top half of the table and face Champions League holders Chelsea on Wednesday in better shape than they could have been.

Why has Allegri struggled to make an instant impact?

Unlike when he took charge in 2014 after Antonio Conte had led Juve to three straight Serie A titles, now Allegri has a rebuilding job on his hands.

Maurizio Sarri may have won the title in his only season in charge but his appointment as Allegri’s successor in 2019 was far from a success, failing to win over key players Giorgio Chiellini and Cristiano Ronaldo, while Andrea Pirlo’s season in charge in 2020-21 was even worse. Juve finished a disastrous fourth.

One of Allegri’s biggest challenges in reshaping the squad is to deal with the loss to Manchester United of Ronaldo, whose steady stream of goals masked the need for change in the team.

The once imperious defence is not impenetrable anymore. Gianluigi Buffon and Andrea Barzagli are long gone. Leonardo Bonucci and Chiellini, despite having proved more than reliable, need a break more often than in the past.

Matthijs de Ligt has not yet lived up to his potential and has not shown the level of performances which prompted Juve to pay £67.5m to sign him from Ajax.

“Since he arrived, you all speak of a future Ballon d’Or [winner],” said Allegri. “We all need to keep calm, he has important qualities but he has to develop.”

This vulnerability in defence is borne out by some stark statistics. The 10 goals they have conceded in their first six league games is more than in any season since the late 1980s. And they have conceded at least once in each of their past 20 league matches, something they had not done for more than 60 years.

Juve’s ability to move on from Ronaldo has not been helped by injuries to key attacking duo Alvaro Morata and Paulo Dybala. Morata left the pitch against Sampdoria on Sunday, while a shaken Dybala took to the changing room in tears during the game. Neither will feature until after the October international break.

They are their team’s joint-top scorers, so their absence will be felt.

The midfield is not working well either. Adrien Rabiot should, according to Allegri, “take to the goal 30 times a game and burst the ball through the net, but he keeps shooting over the bar”.

Manuel Locatelli, part of Italy’s triumphant Euro 2020 squad, will have an increasing role to play following his summer arrival from Sassuolo.

In short, solidity is gone at the back, creativity has been lacking in midfield and the front line is a construction site.

Encouraging signs emerging

“And they want to play for Juve!” Allegri screamed with displeasure while leaving the pitch after a 1-1 draw with AC Milan on 19 September.

Victories over bottom-half sides Spezia and Sampdoria since then can only offer so much encouragement, but there are reasons to suggest Juventus can properly turn a corner.

They have plenty of young talent and the likes of De Ligt (22), Dejan Kulusevski (21) and Chiesa (23) can all have a much bigger impact. All three were only on the bench for that game with Milan.

They still have to prove they have what it takes to wear a Bianconeri shirt – but no-one doubts the quality is there. The same can be said for Moise Kean, who has returned from Everton on a two-year loan which will become a £24m permanent deal.

Knowing his rebuild had to start from the basics, Allegri had been implementing a pragmatic 4-4-2 formation, with Juve defending deep.

On Sunday he opted for a more offensive 4-2-3-1, with Locatelli linking with Dybala, who also took advantage of support from Chiesa and Federico Bernardeschi on either side.

Will the improvements of the past week be enough to trouble Thomas Tuchel’s reigning European champions? Perhaps, but it is more likely this game has come too soon for a side whose manager is mired in the process of identity renewal, on the pitch as well as inside his players’ heads.