Per the trailer, it looks like Captain America, Black Widow, Thor, Bruce Banner, and an unexpected Scott Lang will be leading the charge to work their plan. Meanwhile, Iron Man sits hopelessly on a spaceship, almost out of oxygen, and Thanos celebrates his victory.
Article source: https://www.cinemablend.com/news/2465448/looks-like-jeremy-renners-hawkeye-is-also-in-avengers-endgame-reshoots