San Siro does not forget easily, and the fans in one half of Milan consider Bonucci a traitor no matter what shirt he wears. This summer, Bonucci returned to Juventus after a season at AC Milan - he even captained the side - and it was a move that did not go down well.
The central defender was the subject of a chorus of boos at Milan - Juvenutus on November 11th at San Siro, and the same happened again on Saturday.
It was his home for a season, but even though he was now dressed in the blue of Italy, the Lombardy crowd reacted in the same way.
After the game started it was more of the same. Every time he touched the ball the boos rang out. It draws comparisons with Gerard Pique's treatment by Spanish fans, although it is less political and unique to one stadium.