Aiden McGeady has been told that he can leave Sunderland in January.
It was initially reported by local media that the decision was the result of a training ground incident this week. However, at a press conference on Thursday, manager Phil Parkinson said it involved both on and off field factors.
"I wanted to tell Aiden and his agent early so they can look elsewhere in January," Parkinson told The Chronicle.
It is not a decision I have taken lightly but I am confident it is the right decision. It is a mix of both on the field and off the field that has led to this decision.
The unity of the dressing room is paramount to the club going forward. We have got a good set of lads and they are pulling together. It can get better and we need to work on that but there is a core of very good lads.
Parkinson added that McGeady, who is the club's best paid player, will not be involved in this weekend's game against Blackpool.
The Ireland international moved to Sunderland in July 2017. During the summer, he signed a one-year extension to his deal which was due to keep him at the club until 2021.
The 33-year-old has played 21 times in all competitions for the club this season, scoring six goals on providing two assists.
Sunderland are currently 11th in League One. Parkinson took over from Jack Ross as manager when he was sacked in October.