The Italian football federation has launched an investigation after AC Milan defender Kevin Constant walked off the pitch in protest at crowd racism during a pre-season match on Tuesday.
The incident happened as his team played Sassuolo during the pre-season Trofeo Tim tournament in Reggio Emilia. Serie A newcomers took the trophy with a 2-1 victory.
With the teams level at 1-1, Constant kicked the ball into the crowd and left the field of play as team-mate Daniel Bonera attempted, without success, to persuade him to carry on.
"The Federal Prosecutor's Office has opened an investigation to ascertain the extent of the racist incident that took place yesterday evening at the Stadio del Tricolore in Reggio Emilia during the Milan-Sassuolo match (Trofeo TIM), which saw AC Milan player Kevin Constant the subject of chants from some supporters in the stands," the federation said in a statement.
In January, when Kevin-Prince Boateng took exception to racist chants during a friendly and walked off the field, he was followed by his team-mates, but that was not the case on this occasion.
Mario Piccinocchi, 18, took Constant's place and, speaking after the game, Milan coach Massimiliano Allegri said his club would deliver an official statement in due course and he would instead concentrate on the football.
"We had lots of youngsters on the field and it was a good test in every aspect," he said. "We get our national team players back tomorrow, and then we start preparing for the [Champions League] play-off."
Juventus were the third team in the tournament, and coach Antonio Conte fielded both Carlos Tevez and Fernando Llorente, who was taken to hospital and required stitches to a wound just above his left eye, in his attack for the opening game.
Juve lost 7-6 to Milan on penalties after a 0-0 draw, and Conte told Canale 5 television: "We know we can play different to this. I've got to pay compliments to my side who have worked very hard and intensely and therefore had very tired legs today.
"The positive is that we didn't concede, but we didn't show much of what we can do."