And the BBC pundit feels Williams will be going nowhere as a result, with Swansea's move a bold one in the transfer market that shows the central defender is part of the furniture that will not be sold at any price (although, naturally, the £25m valuation suggests there is in fact a price!).
Hartson told Kicca: "Swansea have priced Ashley Williams at £25m. This is the club showing Crystal Palace and other teams they value their captain more than they value money.
"He is not just the club captain he's part of the furniture and will not be sold at any price. Ashley is going nowhere."
If true, the reports will provide a blow for Crystal Palace, who need a new centre-back this summer. There are alternative options for Alan Pardew, however, including his former defender at Newcastle United Fabricio Coloccini.
He has been linked with Olympiakos as well as Palace, though, according to the Shields Gazette, and time is running out for any new signing to bed in as the Premier League season draws nearer and nearer.
For Swansea fans, though, as Hartson states, this is a signal of intent and, hopefully, a stance they won't U-turn on.