Filmmaker James Gunn revealed during a Q&A with fans on Facebook that there are no human characters in leading roles on Guardians of the Galaxy Vol. 2.
Asked whether Deadpool would make a cameo appearance in Guardians, Gunn said that it would be impossible since the character's movie rights are held by Fox. He added that there are no humans in Guardians Volume 2, before cutting himself off, not wanting to continue his train of thought.
Gunn later posted a clarification of his comment from his Facebook live chat. He said there no main human characters besides Peter Quill.
His comment is still pretty interesting given that Kurt Russell is likely join the Vol. 2 cast as an important character, so he's probably not playing a human. Also, since set videos appear to show Earth locations, it sounds like no new primary human characters will be introduced in those scenes.