Stefano Pioli insisted on Monday that AC Milan have turned their attentions to the Champions League opener with Newcastle United after the local derby humiliation at the weekend.

The seven-time European champions were hammered 5-1 by Serie A leaders Inter Milan on Saturday, a brutal defeat which swept away all the positive vibes created by a new-look team claiming three straight wins before the international break.

It was a fifth defeat in as many Milan derbies in 2023, Inter racking up an aggregate score of 12-1 over those matches which include last season's Champions League semi-final.

"We had a lot of faith and positivity for the derby but it didn't go well, there's no point hiding it," Pioli told reporters.

"It was a big disappointment, but we have the Champions League and that is good as it's the only way to switch.

"These defeats in the derby hurt... I'd give everything to change them but unfortunately they went how they went."

Milan have been drawn in a tough Group F which also features Borussia Dortmund and French champions Paris Saint-Germain, and a good start at home to Saudi Arabia-backed Newcastle would be the perfect response to Saturday's disappointment.

"I know I have a good team, this group of players will be able to get over a really difficult derby," said Pioli.

"I owe a debt to the fans because last year when we were struggling, when we were playing really badly, they stayed behind us."

Sandro Tonali will return to the San Siro earlier than expected after being sold to Newcastle in July, one of two big changes over the summer with club icon Paolo Maldini being sacked as technical director.

Italy midfielder Tonali is a boyhood Milan fan and was a key component of the team which won a first league title in 11 years in 2022.

"It will be emotional. Sandro is a great player and was important to us getting where we are today," said Pioli.

"We won together and we grew together, and it will be emotional for him to return to the San Siro. We wish him the very best -- from the next match."

Newcastle come into their first Champion League match in two decades off the back of a 1-0 win over Brentford which halted a run of three straight Premier League defeats.

Tonali is fit to play on Tuesday after recovering from a thigh strain which meant he missed both of Italy's recent Euro 2024 qualifiers and admitted it was difficult leaving Milan.

"I will obviously have strong feelings but I won't know what it means to have come back until I play at the San Siro," said the 23-year-old.

"It was a difficult summer... Milan is the team I support and the team that gave me a chance to realise a dream, I'll have to do my best to manage my feelings."