With “Game of Thrones” nearing an end after its eighth season, talk has long been swirling of a potential prequel or spinoff to keep the valuable HBO franchise alive — and that prospect is perhaps even more appealing to fans following the news that showrunners David Benioff and Dan Weiss are considering shortening Seasons 7 and 8 to less than 10 episodes each, as Variety exclusively revealed.

But Benioff and Weiss tell Variety that any rumors about a spinoff are just that.

“I know that [HBO programming president] Mike [Lombardo] made off-the-cuff comments to that effect,” says Weiss. (Lombardo told reporters at the Television Critics Assn. press tour in January that “there’s enormous possibility to be mined” in a prequel.)

“When we sat down with him and told him, ‘This is what we see, this is how many hours of viable story we have left to tell the story we set out to tell,’ there wasn’t a second of pushback on that,” Weiss insists. “They were concerned with making the best show they can because they know that’s the show that’s going to stick around for the longest.”

Weiss says their concern, which HBO understands, is the challenge of keeping a serialized story interesting for fans.

“At a certain point, especially if it’s a serialized story, it falls apart and loses its heat and its momentum because there’s a carrying capacity even a world the size of ours has,” he points out. “When you reach that carrying capacity and you try to push it further, people start to wonder when this is going to be over and hope that it will be over soon so they can move onto the next thing. That’s not what we ever wanted.”

HBO’s Lombardo, too, now dismisses any plans of a “Game of Thrones” spinoff.

“That’s never the way we’ve done our best work,” he says. “I can’t imagine, if it were not driven by them, that that would happen.”

“Game of Thrones” Season 6 premieres Sunday, April 24 at 9 p.m. on HBO.