Porter joined the programme this season as Blake, a new private investigator at the law firm.
However, King told Staying In With Vlada that Porter will probably leave the show for pilot season.
"He's not going to be kept as a series regular," he said. "I mean, I think we're losing some of these people to pilot season. So we built [his role] with the mind that we'd have to finish his arc by a certain point."
King added: "There is this battle royale between him and Kalinda and obviously... I don't want to give away who wins, but guess."
The Good Wife airs on Tuesdays at 10/9c on CBS in the US and on Thursdays at 9pm on More4 in the UK.