AC Milan steps into Tuesday's Champions League kickoff against Newcastle United with an air of uncertainty after a humiliating derby loss that has raised questions about their overhauled team, set to confront former teammate Sandro Tonali.

The emphatic 5-1 defeat to Inter Milan on Saturday brought an end to Milan's unblemished start to the league season. This bitter loss left disheartened fans demanding the removal of coach Stefano Pioli, particularly following a grueling fifth straight derby setback. This sequence also includes their exit from the previous season's Champions League semifinals at the hands of their local rivals.

Pioli, who guided Milan to their first league title in 11 years in 2022, was roundly criticized for refusing to apologize to fans for their heaviest derby defeat since 1974.

It was a scoreline he insisted was undeserved as it was rounded off with two late strikes from Hakan Calhanoglu and Davide Frattesi.

“I’m fine with the first 70 minutes, it’s the final 15 which need to be forgotten,” Pioli told reporters.

“We should have stayed together as a team right until the end, but instead we got demoralised and became unbalanced. At 2-1 we could have got back into it but the third goal (in the 69th minute) took our legs out from under us.”

The trio of new signings who had so impressed in Milan’s opening three wins – attacker Christian Pulisic and midfielders Ruben Loftus-Cheek and Tijjani Reijnders – were nullified by Inter who have run up an aggregate score of 12-1 in 2023’s five derbies.

The humiliating manner of Saturday’s loss means the visit of Newcastle takes on a new significance as the first match in a tough Group F which also features Borussia Dortmund and Paris Saint-Germain.

Milan came into the new season at a crossroads after the big-money sale of boyhood Milan fan Tonali, who Newcastle coach Eddie Howe said should feature on Tuesday.

That sale was the second half of a painful double whammy after club icon Paolo Maldini was booted from his role as technical director along with sporting director Frederic Massara.

Maldini and Massara signed Tonali and a series of other players who took Milan to the Scudetto. Their departures left supporters wondering which direction the club were taking.

Tonali’s sale was also another sign that the seven-time European champions simply cannot compete with the financial might of the Premier League and a handful of other super clubs.

However Milan, run by American investment fund RedBird, had already tied star attacker Rafael Leao to a contract until 2028 and got to work bringing in a host of new players to deepen their squad.

The early signs were good too, with convincing wins over Bologna, Torino and Roma made more impressive for the immediate impact of Loftus-Cheek, Pulisic and Reijnders.

But on Sunday the Milan-based Gazzetta Dello Sport said that all that good feeling had been “eliminated… swept away by Inter”.

“We’ve grown with every victory, now we need to learn from a heavy defeat,” Pioli said.

“There won’t be any aftermath as this is a mature team. We don’t have any mental problems here.”

Pioli’s team need to show that Saturday’s massacre was a blip rather than a taste of things to come against the top teams.