Anthony Russo, director of Avengers: Doomsday, confirmed that some actors in the film have yet to be announced. Marvel Studios previously revealed a large number of participants, including several actors who appeared in Fox's X-Men film series, but that list was not the complete cast.
While discussing the new film's cast during a Q&A session about Avengers: Endgame, Russo stated, "The cast is very large; we've announced part of it, but there's another part that hasn't been announced." He did not reveal the names or roles of the unannounced actors.
The currently announced cast includes X-Men film series actors such as James Marsden, Rebecca Romijn, and Alan Cumming, as well as Fantastic Four actors like Pedro Pascal and Vanessa Kirby. Chris Hemsworth, Anthony Mackie, and Robert Downey Jr. are also on the list.
As for who has yet to be announced, there is no definitive answer at present. Rumors about the return of characters such as Elizabeth Olsen's Scarlet Witch remain just that; whether Ryan Reynolds' Deadpool and Hugh Jackman's Wolverine will appear has also not been officially confirmed.
Avengers: Doomsday is scheduled for release on December 18.