King spent a spell on loan at Middlesbrough before returning to the Latics in the summer, but he will now be left without a club after a mandatory notice period, believed to be 14 days, has expired.
Whelan: "We have to follow the rules and regulations, which means we will have to give him 14 days notice that his contract will be cancelled.
"He is absolutely sacked - we will not tolerate football players who get sent to jail for 18 months. As far as we are concerned, he is finished with football at Wigan Athletic.
"It sets such a bad example for our youngsters coming through, who are just crazy about being professional footballers.
"Young people look up to professional footballers and we must have standards. At Wigan we're mad keen on setting standards and our players, generally, are absolutely brilliant.
"It can happen to any club - this has happened while the lad was on loan to Hull. I don't blame Hull in any way, shape or form, but we have to stand up and be counted."