The 22-year old, who has scored five goals for Town since his summer move from Newcastle United, was given permission by the club to deal with personal issues but has failed to return to training.
"I don't know. That's all I'm prepared to say,” Cooper told BBC Wiltshire.
"He was never going to play on Tuesday (in their 2-1 win over Wycombe) but he was supposed to be in for training today (Thursday).
"But people should be concentrating on the players who played on Tuesday and that will play on Saturday."
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