Mirko Vucinic has clashed with Juventus fans while with the squad in Chatillon.
The Montenegro international, who has been linked with Manchester United over the weekend, lost his cool after hearing taunts from one fan.
Alfredopedulla.it says Vucinic responded with an expletive-filled challenge to the supporter, before being ushered away by coaching staff.
Vucinic is under pressure at Juve after seeing strikers Carlos Tevez and Fernando Llorente arrive in the summer.