It’s now been made official by none other than James Gunn himself:
Next to how Guardians of the Galaxy Vol 3 will fit together with the upcoming Guardians of the Galaxy Holiday special and how big a role will Thor play in the new film, the big question everyone is asking is, Who is going to play Adam Warlock. Sure, it’s not even really been revealed that he’ll be in the movie, but they’ve teased him in both Vol1 and 2, so it feels inevitable that we’ll be seeing him in Vol 3.
In a new rumor from Cosmic Circus it is being reported that we’ll not only be seeing the cosmic character in the film but that he’ll be portrayed by Will Poulter. Poulter is probably best known for his work on films like The Maze Runner, Chronicles of Narnia, and The Revenant. He also appeared in the Bandersnatch interactive episode of Black Mirror.
While Poulter has been a fan favorite for the role for years, the basis of the rumor seems to be that he recently stepped down from a part in the upcoming LOTR series on Amazon Prime due to scheduling conflicts. If that’s the case, it would be a good clue that Warlock is not only set to appear, but that he’ll be a major player in the MCU in coming years.