Arsenal boss Unai Emery said Granit Xhaka told him that he is not ready to feature in the Premier League clash against Leicester City on Saturday.
Xhaka has not played for the club since he reacted angrily to being booed by Arsenal fans at the Emirates Stadium in their 2-2 draw with Crystal Palace on Oct. 27.
"I spoke with him on Tuesday for how he is feeling now and his mind because he is training well, but he said to me he can't play," Emery told a news conference.
The manager said Arsenal would wait until Xhaka was in the right frame of mind to play for the club again, but later indicated he could not be certain that would happen.
"We need a player like Granit Xhaka. But also, I don't know if he's going to play again," the BBC quoted Emery as saying.
Asked about a possible Xhaka transfer in the January window, the manager said he was not thinking about that because it was only November.
"We're going to play a lot of matches in November and December. We cannot change him in that two months," Emery said. "The club is speaking with him and we're going to decide how he is and how I'm thinking we use him."
Xhaka released a statement days after the Palace match and said he had reached "boiling point" over the amount of abuse he had received in the stands and online.
"The first captain is Aubameyang because he is experienced and he has the respect of the dressing room," Emery added.
"He was the top scorer last year in the league and I know he needs time to take that responsibility 100 percent, but we will support him."
Arsenal are six points behind Leicester and have failed to win their past four games in all competitions.
Information from Reuters was used in this report.