Speaking with Game Informer, creative director Mike Laidlaw and writer David Gaider said that while they knew such news would disappoint fans, the studio wanted to be upfront about it.
However, the sorceress would feature heavily in the game, said Gaider.
“It’s not a cameo. She plays a significant role,” he said.
“The story of Inquisition is [Morrigan’s] moment, which is a good way to think about it,” added Laidlaw.
“The kernel of Inquisition’s story we knew from about midway through Dragon Age: Origins. The story has been in the making for a very long time.”
The witch didn’t feature at all in Dragon Age II; her last appearance was in 2010’s Witch Hunt DLC.
“I think you could say in Dragon Age II, we didn’t go to that story, but it has always been there, waiting for us,” said Gaider.
Prior player decisions regarding Morrigan would carry over into Inquisition, he added.
“The various states that Morrigan can be in – of which there can be quite a few, because we don’t know when to stop when it comes to making decisions – they’re all recognised.”
“[Morrigan] has a human role in this plot, which I think may surprise some people because they might only think of her as a plot device,” said Gaider.
“She has this big plot she’s involved in, and while that’s true to an extent, I’m taking her to a human place. That will make sense after the fact.”
Dragon Age: Inquisition is due out for Xbox 360, PlayStation 3, Xbox One, PlayStation 4, and Windows PC in Q3 2014.