The Midlands club sold Douglas Luiz to Juventus in a surprise transfer over the summer.
Luiz has not played in the past seven games for Juve due to injury, but will hope to eventually settle in Turin.
Asked about Luiz, as the two teams do battle in the Champions League group stages, Emery said: "He must be happy there.
“He must get the challenge there with his quality.
"I am not thinking that he will want to leave there but I don't know.
“I think now is that he is injured and he won't be here tomorrow."
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