Captain Marvel is hailed as the Avengers: Infinity War to take down Thanos.
As revealed in Carol proposing the team simply go after Thanos, leading to the team piloting the Benatar for a space rematch.
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After that, there's no sign of Captain Marvel in the Avengers: Endgame trailers. In footage that appears to be after a time-jump (due to Black Widow's longer hair and the presence of Hawkeye), Carol is nowhere to be seen. Most notably, she doesn't seem to be present in the lead up to the team's big mission with the heroes dressed up in their white-and-red matching suits; she's not present in any shots of the scene, nor do she have one of the "Advanced Tech Suits" in any of the merchandise.
Obviously, there's the possibility that she's edited out of the Avengers: Endgame trailer footage and that she doesn't need a new suit knowing how powerful she is, but what if she's never really a part of the film's primary mission?
Considering everything known about Captain Marvel's role in Avengers: Endgame, it does look like something will happen to Carol Danvers early on the film sidelining her from the primary action.
Since the Tesseract was the source of her powers, the Mad Titan in posession of the Space Stone has the advantage over her. Perhaps Thanos is able to neutralize her, leaving the Avengers with no one but themselves to rely 0n in taking down the intergalactic villain. Worse, she could die early on in the film (only to be brought back once the Avengers succeeds with their endeavor). Either way, it would be a bold move considering Captain Marvel's recent $1 billion success, although an effective way to amp up the drama in the movie.
Similar to what directors Joe and Anthony Russo did with Thor almost defeating Thanos in Avengers: Infinity War, Carol inspiring the heroes to take another swing at Thanos is the perfect set-up for this plot twist. It also serves the Avengers: Endgame's overall narrative by reinforcing the idea that everything boils down to the original six Avengers, with no single hero able to accomplish this mission alone.
Regardless of what her role will be in Avengers: Endgame, Captain Marvel is going to be the face of the MCU as it begins a new chapter in Phase 4. With that comes a slew of future opportunities for her to save the universe from countless threats. At this point, this ongoing narrative belongs to the founding heroes of the franchise, and it makes sense that they'll be the ones to save the day potentially for the last time as a team.
