Sunderland have given Papy Djilobodji notice that they intend to terminate his contract.
The Black Cats have confirmed that 'it has accepted Papy Djilobodji’s repudiatory breaches of contract and notice of the same has been provided to the player.'
Djilobodji is under contract until June 2020.
It is understood that the centre-back was given written permission not to return to the club at the start of pre-season training as he looked to secure a transfer away.
However, he did not return as planned last month and when he did return, he comprehensively failed a fitness test.
With that in mind, it is understood the Black Cats believe he has in essence terminated his own contract, with the 29-year-old at a minimum weeks away from realistically being fit to play.
A club statement reads: "Sunderland AFC has given notice under its contract with Papy Djilobodji. Djilobodji, who was under contract to SAFC until June 2020, indicated in June 2018 that he wished to leave the club.
"In order to facilitate that desire, the club entered into a written agreement with the player allowing him to spend the month of July on voluntary unpaid leave.
"When that period came to an end, the player was expected either to leave for a new club – having reached a deal satisfactory to himself and SAFC - or to return in shape to play professional football. Instead, he returned to Sunderland over a month later, in the first week of September, ignoring written requests for his return.
"On his return, he was subjected to the same fitness test that his fellow professionals had undertaken on their return. He comprehensively failed that test.
"As a result, Sunderland AFC can confirm that it has accepted Papy Djilobodji’s repudiatory breaches of contract and notice of the same has been provided to the player."
The move means the Black Cats will not recoup a fee for a player who cost them around £8 million from Chelsea.
Chairman Stewart Donald recently paid the final instalment on that deal.