CBS All Access' Star Trek: Discovery has been delayed again as the series continues casting.

The revival for the streaming platform has cast James Frain as Spock's father, producer CBS Television Studios announced Wednesday, as sources confirm that the show's planned May debut has been pushed.

"Production on Star Trek: Discovery begins next week. We love the cast, the scripts and are excited about the world the producers have created," reps for CBS All Access said in a statement. "This is an ambitious project; we will be flexible on a launch date if it's best for the show. We've said from the beginning it's more important to do this right than to do it fast. There is also added flexibility presenting on CBS All Access, which isn't beholden to seasonal premieres or launch windows."

Frain will play Sarek, the famed father of Spock who was first introduced in the original Star Trek and who has made several appearances throughout the franchise's many incarnations over the past five decades.

The CBS All Access show features the franchise's Enterprise, now known as the U.S.S. Discovery. The drama will introduce new characters seeking new worlds and civilizations while exploring the dramatic contemporary themes that have been a signature of the franchise since its inception in 1966.