Watch Mark Ruffalo’s Big ‘Avengers 4’ Reveal on ‘The Tonight Show’

Hulk star Mark Ruffalo visited The Tonight Show to tell Jimmy Fallon some juicy Avengers 4 [...]

Hulk star Mark Ruffalo visited The Tonight Show to tell Jimmy Fallon some juicy Avengers 4 spoilers — but Ruffalo, well-known for his loose lips, was censored.

Ruffalo's secret-spilling tirade comes as Marvel Studios gears up to officially launch its Avengers 4 promotion, which chief Kevin Feige said would happen after the studio first got eyes on Captain Marvel.

Fans were hopeful Ruffalo would officially announce the top secret title in response to a rumored title leak that surfaced Thursday.

Fervently kept under wraps, the title has continued to fuel endless speculation — prompted in part by knowing teases carefully curated by directors Anthony and Joe Russo.

Marvel Studios chief and mastermind Kevin Feige admitted earlier this year the secrecy around the title "backfired" and the furor around it has "gotten entirely out of hand."

"And now will have no chance to live up to any expectations of what it's gonna be," Feige told IGN. "And it sort of backfired, if I'm honest with you, because the notion was to not talk about it so the focus was to be on [Infinity War]."

Feige said the decision to hold off on revealing the Avengers 4 title was birthed out of a late 2014 slate presentation where Feige personally announced a slew of anticipated films like Black Panther and Infinity War, which he said overshadowed the soon-to-release Avengers: Age of Ultron.

"Ultron hadn't come out at that point and I felt a tiny little sense of, 'Well, gosh, we've gotta talk about the movies we have coming out next because that's what we've been working so hard on and that's what's next available for our audience to see,'" Feige said.

"But when we talk that far ahead, that took a lot of attention out [of impending movies]."

More recently, Feige ruled out the Infinity Gauntlet title, saying the sequel "definitely" won't borrow its name from the 1991 comic book that partially inspired the two films.

With Captain Marvel now having released its anticipated first looks, Marvel will soon turn its attention towards promoting Avengers 4, as confirmed by Feige this summer. "[Avengers 4 promotion will] be towards the end of the year with however we launch that film," he said.

Captain Marvel releases March 8, followed by Avengers 4 May 3 and Spider-Man: Far From Home July 5, 2019.