Williams has been struggling with an ongoing ankle problem, which forced him to withdraw from Wales's upcoming World Cup qualifier, and Coleman has insisted that the Welsh skipper will not be ready to return after the international break.
The 43-year-old told the South Wales Evening Post: "I've talked to Ashley, he was here on Monday and we scanned him immediately. It was clear that he wouldn't be able to play and I don't suppose that he'll be back for Swansea's next game or the one after that. How quickly the injury settles down, I don't know.
"Looking at the scan, talking to our medical team and liaising with Swansea, it was never going to happen.
"Michael Laudrup said that he had him on the bench for the Southampton game as a number, and looking at the injuries that he's got, I can see that. He was never going to play. I'm not sure when he'll be back, probably two or three games after this international camp."
Williams has featured just twice for the Swans since picking up the injury at the start of September.