The series, which begins its seventh season on Monday, September 20 stars Emmy Award nominee Hugh Laurie, along with Lisa Edelstein, Olivia Wilde, and Robert Sean Leonard.
Bergen, who will play the mother of Edelstein's character, Cuddy, will appear in a benefit performance of Evening Primrose next month in New York. She is a multiple Emmy Award winner for her work on Murphy Brown.
Baker, who was seen last season in God of Carnage, received a 2009 Emmy Award nomination for his guest starring role on The Good Wife. Grey will also appear this season on Dancing with the Stars. Irving will play the title role in the Project Shaw presentation of Candida later this month and recently starred in A Little Night Music. Lillard is best known for his work in the movie Scooby Doo.