Pickens, who plays Dr. Richard Webber on the ABC series, told Us Weekly magazine that Heigl and Knight are leaving.
Pickens says he wishes Heigl "nothing but the best," the magazine reported online Tuesday. He says his other co-star, Knight, wants to pursue other "career paths."
Publicists for Knight and for series creator Shonda Rhimes declined comment. Requests for comment from Heigl's publicist and ABC were not immediately returned.
Heigl, who plays Dr. Izzie Stevens, starred in the films "Knocked Up" and "27 Dresses," and has another movie, "The Ugly Truth," coming out.
What the El!?! Editorial:
FINALLY… I'm over both these characters so it'll be nice to be done with them once and for all!
Izzie's love fest with ghost Denny has been getting old.
Demi Moore was in love with a Ghost but it was over after 128 minutes for crying out loud!
And George? Has he had more than three lines per episode this year?
I'm ready for a shakeup on the show… it's about time.