As the marketing machine for The Avengers: Age of Ultron continues to roll out – already projecting to help the film enjoy the biggest opening weekend in history – it’s becoming more and more evident that whatever the studio has in mind for its green-skinned juggernaut, they’re keeping it to themselves. The Incredible Hulk will continue to act as the team’s muscle, but aside from a fight with Iron Man, his arc in the film has been kept under wraps.

But in discussing what may lie in store for Hulk (an adaptation of “Planet Hulk” almost always included) in the future, actor Mark Ruffalo may have let slip some potentially massive spoilers for Age of Ultron, as it pertains to his character. There have been plenty of rumors surrounding Bruce Banner in the film, so those wishing to remain surprised should stop reading now. You have been warned.

To this point, the prospect of a solo Hulk movie has been spoken about quite openly and honestly by all involved at Marvel. And when discussing such a film, it’s impossible not to bring up “Planet Hulk” – a story sending Hulk into a savage alien planet and emerging as its king – and “World War Hulk” which followed. That may be a commentary on the number of “Hulk” comic arcs actually suited to live-action, but that’s for fans to debate.

When Ruffalo and co-star Scarlett Johansson were speaking with IGN about the future of the films, Mark Ruffalo spoke quite candidly – potentially far more candidly than Marvel would have liked:

Mark Ruffalo: “I think there’s a lot of places to go with him [Hulk].”

Scarlett Johansson: “Like where?”

IGN: “Space?”

Ruffalo: “Well he’s going to space. Yeah, I mean there’s some talk of maybe Planet Hulk.”

Unfortunately, IGN doesn’t clarify whether Ruffalo was stating that his character will head into space in Avengers 2 (as has been rumored for some time) or if he is speaking about the comic book version. Similarly, it isn’t specified whether the “talk” of Planet Hulk means conversations at Marvel, or the endless debate among fans. Ruffalo would later state that he has yet to have any “active talks” about a Planet Hulk movie, but reiterating that Marvel is considering a Hulk solo movie once more.

On the surface, Ruffalo’s statements suggest that Age of Ultron may, in fact, lay the foundations for Hulk’s trip into space – whether it is a self-inflicted exile, or his allies judging him too dangerous to remain on Earth. That should obviously be taken with several grains of salt, considering the unclear nature of his comments, as we pointed out. Although he has yet to actively discuss a solo film, Ruffalo maintains that he would be “completely interested in entertaining” the possibility.

But his previous statements on the matter remain just as valid: Planet Hulk may not be the best step for the character to take just yet.

It’s true that no film version of Hulk has been so warmly received as that introduced with The Avengers. However, that’s largely due to Ruffalo’s performance as Dr. Bruce Banner, meaning Marvel could sabotage their succes by building a film that replaces Ruffalo with a CG creation for most, if not all of the story. Considering how well the human/Hulk dichotomy, and Banner’s efforts to accept his dual nature have gone over with audiences, Ruffalo is right to cast doubt on the idea – and producer Kevin Feige agrees wholeheartedly.

That doesn’t mean Hulk is bound to Earth, or intending to remain as a member of his super-team for the foreseeable future (especially not after he is turned against them). If the version of the hero seen in Age of Ultron is as “mature” as Ruffalo has suggested, then all plans are subject to change. But with Civil War and the Infinity War on the horizon, it’s best to assume Bruce Banner won’t be invading and conquering an alien planet any time soon.

Are you disappointed that a concrete plan is not yet in place? Or do Ruffalo’s comments have you convinced there’s more to this story than is being let on? Hopefully when Age of Ultron releases to the public, more answers can be found (and hotly debated).

Marvel’s “Avengers: Age of Ultron” stars Robert Downey Jr., who returns as Iron Man, along with Chris Evans as Captain America, Chris Hemsworth as Thor and Mark Ruffalo as The Hulk. Together with Scarlett Johansson as Black Widow and Jeremy Renner as Hawkeye, and with the additional support of Samuel L. Jackson as Nick Fury, Don Cheadle as James Rhodes/War Machine, Cobie Smulders as Agent Maria Hill and Stellan Skarsgård as Erik Selvig, the team must reassemble to defeat James Spader as Ultron, a terrifying technological villain hell-bent on human extinction. Along the way, they confront two mysterious and powerful newcomers, Wanda Maximoff, played by Elizabeth Olsen, and Pietro Maximoff, played by Aaron Taylor-Johnson, and meet an old friend in a new form when Paul Bettany becomes Vision.

The Avengers: Age of Ultron will be in theaters May 1, 2015; Ant-Man on July 17, 2015; Captain America: Civil War - May 6, 2016; Doctor Strange - November 4, 2016; Guardians of the Galaxy 2 - May 5, 2017; Spider-Man reboot – July 28, 2017; Thor: Ragnarok - November 3, 2017; The Avengers: Infinity War Part 1 - May 4, 2018; Black Panther - July 6, 2018; Captain Marvel - November 2, 2018; The Avengers: Infinity War Part 2 - May 3, 2019; Inhumans - July 12, 2019.