The comedy - from exec producer Stephen Falk (Weeds) - will star Cook as a sexist, hard-drinking radio host.
Devlin will play Mason, another host who is Cook's workplace rival, reports TV Line.
He will be credited as a guest star in the pilot and will likely recur if Next Caller Please is picked up to series.
The actor is best known for appearing on Brothers & Sisters and Cougar Town. His former Cougar Town co-star Collette Wolfe will also appear in the Next Caller Please pilot as Cook's new co-host.
Joy Osmanski (Grey's Anatomy) will star as a radio producer who hires Wolf's character Stella.
My Name Is Earl's Marc Buckland has been hired to direct the project, which is produced by Lionsgate TV.
Other NBC pilot pick-ups include political comedy 1600 Penn, starring Bill Pullman and Jenna Elfman, and a sitcom produced by Late Night host Jimmy Fallon.
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