In Captain America: The Winter Soldier, directors Joe and Anthony Russo made a point of created an extended supporting cast for Captain America through the inclusion of Black Widow and Nick Fury and the introduction of The Falcon.
Yesterday, comments from Jeremy Renner started rumors that Captain America 3's cast may grow even larger, with the inclusion of Hawkeye.
Even considering all of that, new comments from Joe Russo suggest that he may be envisioning something of a much larger scale, telling Cinema Blend that he wants to see the classic Marvel Comics crossover Secret Wars brought to the screen.
"Listen, when I started collecting, The Secret Wars was one of the first books I ever bought, so that's always been an obsession of mine to see something of that scale done – a crossover. I don't know if that would ever be possible, with all the different situations at the studios. But I would love to see a lot of characters on screen together."
Seeing Secret Wars, a comic book that took basically every Marvel Comics character and threw them into battle on an alien planet, done any kind of justice on screen is likely a pipe dream, seeing as – despite many creative types involved with superhero movies saying it's something they'd like to see – the various studio executives and producers involved in the superhero movie making business have said time and time again that there's simply no incentive for them to pursue an inter-studio crossover film.
Captain America 3 opens in theaters May 6, 2016.