Keita Balde Diao is reportedly furious and demanded a Lazio transfer, alerting Liverpool and Arsenal.
The 20-year-old forward was benched in Saturday’s 2-0 Italian Super Cup defeat to Juventus.
According to the Corriere dello Sport, he engaged in a row with President Claudio Lotito after the final whistle, spotted pointing angrily to the bench and the area where he had been warming up in vain.
Keita has been very impressive in pre-season, but was not given a chance to shine in Shanghai.
He reportedly demanded a transfer amid interest from Liverpool and Arsenal.
The asking price is believed to be around €15m for the former Barcelona youth academy product.