What's less clear is where exactly Crossbones fits in this: he's not a major player or someone you'd particularly expect to be involved in Avengers 4, so it begs the question of which moment involving him they're going back to?
Weber also included that Feige confirmed Guardians 3 is "on hold", which doesn't come as a huge surprise, as the news had already circulated after the firing of director, James Gunn.
According to Weber's Twitter, Feige told him fans should expect a trailer for Avengers 4 by the end of the year (which, we assume, would reveal the movie's title), and that Guardians of the Galaxy Vol. 3 is now on hold.
Fans are pretty sure that somehow all those who were dusted in The Snap will becoming back. Will it be time travel?
Grillo himself confirmed on the UFC Unfiltered podcast that he'll appear in "Avengers 4".
Here's what we already know about "Avengers 4": leaked photos from the set that surfaced earlier this year appear to show Chris Evans sporting his Captain America uniform circa 2012 in a set that resembled the climactic Battle of NY from the first superhero team-up film.More news: Gary Neville speaks out on Liverpool winning the Premier League
"He makes an appearance in the next Avengers movie, but it's a flashback", said Grillo.
Though Grillo calls it a flashback, this might be time travel, a possible solution to defeating Thanos. Other theories include the all-powerful time stone and Binarily Augmented Retro-Framing, tech introduced by Iron Man that allows the user to revisit traumatic memories of the past.
He won't be returning in a typical way though, as Crossbones dies in Captain America: Civil War. Unsurprisingly, Feige did not get into specifics, but he did say we will see the trailer "before the end of the year".
"Avengers 4" will feature a blast from Captain America's past.