According to news agency ANSA, Paul Pogba tested positive for testosterone in a standard doping test taken after Juventus played Udinese this season.
The Serie A match ended 3-0 at the Dacia Arena in Udine on August 20, but Pogba remained on the bench throughout.
He did come on for brief substitute appearances in the next two rounds against Bologna and Empoli.
Nonetheless, Pogba was still one of the players randomly drawn to undergo doping tests and it is reported there were elevated levels of testosterone.
A second test sample must now be checked before it can be said he has failed the doping test.
It has been a disastrous time for Pogba at Juventus since the return as a free agent from Manchester United last summer, barely featuring due to a series of injury problems.
These reared their head again last week when he pulled up with another muscular issue during the 2-0 win away to Empoli.