Inter Milan defender Francesco Acerbi lost his cool after a Club World Cup fan wearing a Paris St Germain shirt in Seattle taunted him about last month's Champions League final, with the Italian threatening to beat him up if the teasing continued.

Italian club Napoli said they were "stunned" after Italy's football federation (FIGC) on Tuesday dropped a probe into alleged racist comments made by Inter Milan's Francesco Acerbi to Napoli's Juan Jesus due to lack of evidence.

Francesco Acerbi on Monday left Italy's training camp ahead of two friendlies in the United States after reports he will be investigated for alleged racial abuse of Napoli defender Juan Jesus.