Source: Knight Out, Heigl In On `Grey's Anatomy'

Dr. George O'Malley is checking out of "Grey's Anatomy" but Dr. Izzie Stevens is likely to remain on staff.

A person with knowledge of contract negotiations with T.R. Knight, who plays George on the ABC drama, said Thursday the actor is leaving the show. The person, who wasn't authorized to discuss the negotiations publicly, asked not to be identified.

But the person said that negotiations with Katherine Heigl (HY'-guhl) were more successful and she's expected to return as Izzie.

The season finale in May left the fate of George and Izzie unclear, with both characters at death's door _ or possibly beyond it.

A publicist for Knight declined comment. Heigl's representative did not immediately respond to an e-mail request for comment.