The news was confirmed by co-star James Pickens Jr. who plays Dr. Richard Webber. He says Knight wanted to pursue other career paths. As for Heigl, she's ready to move on, sources say.
Knight has talked with executive producer Shonda Rhimes several times, Us Weekly reports. The question is left unanswered as to how George can make a believable exit. Can they write him out in a way that will let him come back someday?
Heigl's and Knight's people didn't comment. And ABC and ABC Studios didn't confirm their departures. So long, dear doctors. The ER will miss you.