Vin Diesel was never officially announced as being in the slated Inhumans movie, but due to his rather small role in Guardians of the Galaxy and some less-than-subtle social media posts, it was presumed that the actor would be playing the King of the Inhumans, Black Bolt. Since the character very rarely speaks (his superpower is his too-destructive-for-its-own-good voice), it seemed like a natural fit alongside the single-sentence-spouting Groot. But according to Guardians of the Galaxy Vol. 2 writer-director James Gunn, the casting isn’t meant to be.
Inhumans was originally planned as a movie in the Marvel Cinematic Universe, but Marvel recently announced that it has been changed to a TV series. When asked on his Facebook page about the possibility of Diesel appearing on the show, Gunn said, “The Inhumans’ is going to be a TV show. Unless Vin wants to take a huge pay cut and sign up to do a TV show it seems unlikely.”
With one sentence, Gunn pretty much confirmed Diesel’s involvement in the Inhumans movie and then subsequent non-involvement with the show. Maybe if Diesel is really dedicated to the character, he would join a TV show—movie stars can make big money acting on TV nowadays, after all—but Inhumans wouldn’t exactly be prestige television.
You can see the Facebook comment exchange for yourself here.