The midfielder was sent on-loan to Turkey, having only signed for Sunderland in January.
A source close to N'Diaye told the Sunderland Echo: "It was a surprise when Alfred was told that he wasn't part of Paolo Di Canio's plans at Sunderland. He was enjoying himself there and the fans seemed to like him.
"But he knew the coach at Eskiehirspor from his time at Bursaspor, so it was a good move for him. It doesn't mean he will stay there next summer.
"He will see how he progresses over the season and then make a decision."
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