Anson Mount and Rebecca Romijn are not expected to reprise their roles as Captain Christopher Pike and Number One,
They reportedly signed one-year contracts for the CBS All Access series to end with the second season.
Mount was revealed to be involved in an on-set altercation with a director this past August, making physical contact with the director while discussing a scene.
The incident apparently had nothing to do with Mount leaving the series. The production reportedly is interested in finding ways to work with him again.
The report did not state whether or not Ethan Peck would be returning in Season 3 as a younger version of Spock.