Sunderland have served Didier Ndong notice on his contract.
The 24-year-old returned to the North East in recent days after being AWOL for the entire pre-season programme.
The Gabon midfielder had failed to negotiate multi-million pound moves to Torino and Benfica in the summer, with the club happy to allow him to move on.
In recent days he was quoted in the Gabonese media as saying he was willing to return and play his part in a League One promotion push, but that was given short shrift by the Sunderland hierarchy.
Like Papy Djilobodji, they have now served him notice that they intend to terminate his contract.
Further legal action is likely as the Black Cats seek to recover a significant loss on their investment.
They had agreed a fee in the region of £7 million with Serie A side Torino for his services not long ago.
Ndong became a record signing when he joined the club from Lorient in 2016.
He had three years left to run on his current deal.