Jason Isaacs is the latest cast member to come aboard CBS All Access’ upcoming series “Star Trek: Discovery,” Variety has learned.

Isaacs will play Captain Lorca, the captain of the Starship Discovery.

Isaacs is one of the most high-profile names to be cast in “Star Trek: Discovery.” He joins “The Walking Dead” actress Sonequa Martin-Green, who will star as the lead lieutenant commander, plus James Frain as Spock’s father Sarek, Anthony Rapp as a space fungus expert, and Michelle Yeoh as the captain in charge of the Starship Shenzhou. Other cast members include Starfleet officers, played by Terry Serpico as Admiral Anderson, a high-ranking official of Starfleet; Maulik Pancholy as Dr. Nambue, the chief medical officer of the Starship Shenzhou; and Sam Vartholomeos as Ensign Connor, a junior officer in Starfleet Academy assigned to the Starship Shenzhou.

“Star Trek: Discovery” was originally set to launch CBS All Access in January 2017, but the hotly anticipated series has been repeatedly delayed and now is pushed to debut late this summer or in early fall. The CBS streaming service was instead kicked off with the help of “The Good Wife” spinoff, “The Good Fight.”

Sources say difficulties casting and behind-the-scenes flux, including Bryan Fuller stepping down as showrunner, are cause for the show’s delay. Last week, CBS Corp. boss Leslie Moonves spoke at an investor conference, saying he was confident in the quality of the series, and the delay is due to requiring a lot of post production. “It’s important to get it right, and ‘Star Trek’ is the family jewels,” Moonves said.

“Star Trek: Discovery” hails from CBS Television Studios, Alex Kurtzman’s Secret Hideout, Bryan Fuller’s Living Dead Guy Productions and Roddenberry Entertainment. Exec producers are Kurtzman, Fuller, Heather Kadin, Gretchen J. Berg, Aaron Harberts, Akiva Goldsman, Rod Roddenberry and Trevor Roth.

For Isaacs, “Star Trek” is his latest streaming series, following Netflix’s “The OA.” Prior, he starred in USA Network’s “Dig” and NBC’s drama series “Awake.” His film credits include “The Patriot,” “Peter Pan” and the “Harry Potter” franchise. Coming up, he’ll appear in Weinstein Company’s “Hotel Mumbai” and Armando Iannucci’s film “Death of Stalin.”

Isaacs is repped by Gersh and Jackoway Tyerman.