The former "Boston Legal" star will not return for a ninth season of the still highly-rated NBC comedy.

James Spader will not be returning to The Office.

In another shake-up at NBC’s long-running comedy, the Boston Legal actor has opted not to be part of the series’ ninth season, assuming one is ordered, NBC confirmed to The Hollywood Reporter.

Spader has offered the series a dose of star power since veteran star Steve Carell (Michael Scott) exited the series. In the months since, Spader has replaced Kathy Bates’ character as the fictional company's new chief executive, Robert California.

To hear Office executive producer Paul Lieberstein tell it, Spader already has contributed far more to the series than he had planned. The actor had signed to play a two-scene role in the season-seven finale, but the “life and intrigue” that he brought to the part made two scenes become a full season.

"James always wanted this to be a one-year arc, and he now leaves us having created one of the most enigmatic and dynamic characters in television,” adds Lieberstein, who plays Toby Flenderson on the show. “He’s been a great friend to me and the show, helping us successfully transition into the post-Michael Scott years, and I’m grateful for that.”

The news of Spader's exit comes as other members of The Office's staff — on-camera and off — are toying with departure. Head writer Daniel Chun inked an overall deal with rival ABC Studios in late February, mere weeks after his fellow Office writer and star Mindy Kaling (Kelly Kapoor) had her comedy project ordered to pilot at Fox. If the latter is picked up to series, Kaling, whose Universal Television deal expires in June, is expected to depart the Office and focus on the new show.

Although sources have downplayed its likelihood in recent weeks, NBC is also said to be eyeing a potential midseason spin-off centered on Rainn Wilson’s quirky Dwight Schrute character. The idea, which Wilson has since confirmed, is to further explore the Schrute family farm, with multiple generations of Schrutes involved. If the network opts to move forward with it, Wilson, too, likely will pack his bags.

Email: Lacey.Rose@THR.com; Twitter: @LaceyVRose