Fans should expect "Avengers 4" to be longer than "Avengers: Infinity War," which is currently the longest film in the Marvel Cinematic Universe.

"Infinity War" is opening this week -- big L.A. premiere tonight, careful of spoilers! -- and then fans can look forward to "Avengers 4" in May of next year.

Collider sat down with directors Joe and Anthony Russo, who didn't quite confirm that "Avengers 4" will be titled "Avengers: Infinity Gauntlet" but they smiled and didn't deny.

The Russos were asked about the run time of "Avengers 4," and whether it could be a three-hour film or would Disney say that's too long. The directors said Disney has never given them any notes on run time. "Infinity War" is about 2.5 hours, and the Russos said "Avengers 4" is likely to be longer.

Joe Russo: "I'll say it could easily be a three-hour film, but I think that we're very hard on the material. We like it to play at a certain pace. I'm sure that we'll squeeze it. So I can't imagine..."

Anthony Russo: "We have a whole year of work left on that movie."

Joe: "I do think it will be longer than 'Avengers 3.'"

Anthony: "It's clearly impossible to say at this point."

Joe: "You like how we're like -- I'm like 'It's gonna be longer,' he's like 'We can't say!'"

Anthony: "I'm just saying there's such a long road on this movie left."

Joe said the rough/assembly cut for "Avengers 4" is their longest yet, but it's not four hours or anything. Anthony really emphasized that the assembly cut isn't even complete.

Chris Evans (Captain America/Steve Rogers) is said to be leaving the MCU after "Avengers 4" and in that initial report it said he'd be finished after the planned reshoots this fall. So we already know more material will be added to "Avengers 4" later this year, and that must make it especially tough to gauge a run time.

Watch their full interview for more:"Avengers 4" is meant to have a very different tone to "Avengers 3," with the screenwriters saying they're almost like two completely different genres, tonally and structurally.

"Avengers 3" opens this Friday, April 27; "Avengers 4" -- whose title will be announced at some point in the next few months -- opens May 3, 2019.

The big "Infinity War" premiere is tonight. The Russos shared another message on that...

#ThanosDemandsYourSilence

A post shared by The Russo Brothers (@therussobrothers) on

You shouldn't avoid social media altogether. We're curious at the general reaction from critics, who usually post non-spoilery initial reactions right after the premiere. They'll probably tease what they liked/didn't like about the movie, compared to previous MCU films.

Want more stuff like this? Like us on Facebook.