Italy goalkeeper Gianluigi Donnarumma's agent Mino Raiola has accused AC Milan of failing to defend him from the abuse he suffered on his return to the San Siro in Wednesday's Nations League defeat by Spain.
The 22-year-old stopper was given a hostile reception in the Azzurri's 2-1 loss as he played at the home of his former club for the first time since swapping Milan for PSG in the summer.
Donnarumma endured boos and whistles from a section of the crowd every time he touched the ball in the loss to Luis Enrique's side, which followed on from a series of abusive banners.
One banner unfurled inside the ground before kick-off on Wednesday, read: 'Donnarumma, piece of s*** you'll never be welcome in Milano again.'
It was not the first time the Milan ultras had taunted Donnarumma, with Italian supporters hurling abuse at him while playing for the U21 national side.
Donnarumma was Italy's penalty shootout hero in the Euro 2020 final win over England and was named Player of the Tournament over the summer, yet it appears his former club's supporters are unable to forgive his controversial switch to the French giants.
But Raiola has laid the blame for the abuse his client was subjected to on Wednesday squarely at the feet of AC Milan, insisting the Serie A club should have done more to protect him.
'I am disgusted about the boos to Donnarumma and I ask myself why Milan didn't intervene in some way after that banner,' he told Il Corriere dello Sport.
He added: 'Do you want to talk about threats?'
'Has he killed somebody? I don't think so. The truth is that Milan didn't have the strength to keep him, but it doesn't make the difference.
'Ask, anybody, ask a dad. What would he suggest to his son? Join PSG or stay at Milan?
'What happened at the stadium is sad, strange and shameful.
'It's strange that Milan fans only target Donnarumma, only because he made a free choice.
'It's also strange and disappointing that Milan didn't distance themselves from this unacceptable behaviour.'
Spain midfielder Sergio Busquets was seen to offer some sympathetic support during the match as the boos rang out for Donnarumma.
And Raiola said: 'Italy looked bad in front of the whole world. I really appreciate Sergio Busquets' gesture, he understood the situation and what Gigio was going through.
'Gigio has always given everything to the national team, contributing to winning the Euros and being named the best player in the competition.
'He also helped Milan, he remained loyal in the most difficult moment for the club, being professional until the very last day and helping the team to return to the Champions League.'
Former Juventus and Roma manager Fabio Capello had called on Italy fans to not boo Donnarumma on Wednesday night, even though the Italian manager admitted the goalkeeper had been 'ungrateful' to Milan and their supporters.
Speaking ahead of Wednesday's clash, Capello said: 'I hope they will fulfil his desire because he is a national team player who has given an enormous contribution.
'However, let me say that he was ungrateful to Milan. After all the club did for him and his family when he was a kid, he should have behaved differently.'