It's pretty obvious Avengers: Infinity War is going to be Marvel's biggest movie yet. This is the culmination of what they've been building to since 2008's Iron Man and necessitated it be split into two separate movies. We already know pretty much every Avenger new and old will be a part of it, but is that all? Not by a long shot, and the number of characters that could appear on screen should be enough to shake Thanos down to his purple socks.
According to the Russo Brothers while attending Wizard World New Orleans (via CBM), there could be literally dozens of characters showing up in the film...
“We have so many characters we’re dealing with. We’re breaking ground on Avengers: Infinity War. We have a board with 67 characters on it.”
67??? Okay, now obviously that's more than just Avengers. We have to assume some of their non-powered friends like Dr. Selvig (Stellan Skarsgard), Maria Hill (Cobie Smulders), and Pepper Potts (Gwyneth Paltrow) will show up, and Thanos has likely assembled an army, as well. Still, that seems like an incredibly unwieldy group for any director to contend with. There's no chance we could see any of the TV characters show up, is there? Probably not.
Avengers: Infinity War Part 1 opens May 4, 2018; while Part 2 will open on May 3, 2019.