A new clip seemingly pulled from the recently-released Marvel Studios Infinity Saga box set sees Spider-Man (Tom Holland) saving the Guardians of the Galaxy during the big battle with Thanos on Titan in Avengers: Infinity War. In the clip, a spectral version of Doctor Strange (Benedict Cumberbatch) tells Peter Parker to "protect the Guardians," explaining that Thanos (Josh Brolin) had separated their souls from their bodies. He adds that if they were kept apart for too long, the Guardians would die. When Peter objects that he doesn't know what to do about that, Strange says that Mantis (Pom Klementieff) does.
That kicks off a long process of Peter rescuing the Guardians' bodies so that Mantis can help reconnect them with their souls. In what was more or less par for the course in Infinity War, once it's all done, there's a joke made at the Guardians' expense by Spidey.
You can see the scene embedded in the tweet below.
Avengers: Infinity War Deleted Scene... pic.twitter.com/yQv8755RO2— Adam Khan (@AdamKhan100) November 28, 2019
Comments in the thread point out that this scene is where a previously-leaked image featuring Doctor Strange telling Spider-Man "They're not dead yet" came from.
Ultimately, this whole sequence was likely cut for time; Infinity War was already a long movie, and while the fight with Thanos was a high point of the film, doubling its length might not have made the fight better, just longer. Since the notion of the Guardians being separated from their souls was relatively self-contained, you can see how easily it was excised.
This is just one of a number of such ideas or subplots. Recently it was revealed that the relationship between The Hulk and Black Widow, which was established through a couple of movies ahead of Endgame, was more or less abandoned for time, rather than story, when it came time to make the final installment of the Infinity Saga.
Black Widow opens May 1, 2020. Other upcoming Marvel Studios projects include The Falcon and The Winter Soldier in fall 2020, The Eternals on November 6, 2020, Shang-Chi and the Legend of the Ten Rings on February 12, 2021, WandaVision in spring 2021, Loki in spring 2021, Doctor Strange in the Multiverse of Madness on May 7, 2021, Spider-Man 3 on July 16, 2021, What If? In summer 2021, Hawkeye in fall 2021, Thor: Love and Thunder on November 5, 2021, and Black Panther 2 on May 6, 2022.