The third and fourth Avengers movies were first announced as Avengers: Infinity War Parts 1 and 2. Marvel has since retitled the films, keeping Avengers: Infinity War for the film releasing in 2018 while the fourth Avengers movie remains untitled, and that change is more than just a cosmetic one.

Director Joe Russo tells ComicBook.com at Comic-Con International: San Diego that the third and fourth Avengers movies are different creations, each with their own very different characteristics.

‘They’re all big,” Russo says. “It’s important for both movies to be distinctly different. It's important for them to have different tones, and different narratives, and different surprises for the audience. We’ve worked really hard with [writers Christopher Markus and Stephen McFeeley] at ensuring that the films are tonally different and structurally different.”

Russo went on to note the intense filming schedule involved in making these movies, revealing that production on Avengers 4 is starting sooner than most would have expected.

"It's crazy man, we just wrapped the first movie a week ago and I start shooting the second one in two weeks. It’s a crazy schedule," Russo said.

That means Avengers 4 will enter production a full nine months before Avengers: Infinity War opens in theaters. It’s a logistical necessity if Marvel Studios wants the fourth Avengers movie to open just a year after Avengers: Infinity War, as is currently the plan, but it still says something about the confidence that Marvel has in the Russo brothers as directors.

Avengers: Infinity War currently has a 4.34 out of 5 ComicBook.com User Anticipation Rating, making it the most anticipated upcoming comic book movie among ComicBook.com readers. Let us know how much you're looking forward to Avengers: Infinity War by giving it your own ComicBook.com User Anticipation Rating below.

Avengers: Infinity War brings the Guardians of the Galaxy together with the Avengers to face off against Thanos and his minions.

Avengers: Infinity War is directed by Anthony and Joe Russo, from a screenplay by Christopher Markus & Stephen McFeely, and stars Robert Downey Jr., JoshBrolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, JeremyRenner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, PaulBettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Benicio delToro, Tom Holland, and Anthony Mackie.

Avengers: Infinity War opens May 4, 2018.

More Avengers: Infinity War News: Director Discusses When The Avengers: Infinity War Trailer Will Be Released / Check Out The Full Triptych Comic-Con Poster For Avengers: Infinity War / Director Teases High Stakes And Imminent Death In Avengers: Infinity War / Director Explains Why Thanos Needs The Black Order