TVGuide.com reports that Mariette Hartley and Kathy Baker will also make appearances on the Sept. 25 premiere episode. The three women will play friends who all require care at Seattle Grace Hospital. The two-hour season premiere will also see the return of Jeffrey Dean Morgan as Denny Duquette.

"Grey's Anatomy" airs Thursdays on ABC-TV at 9 PM ET; check local listings. Visit http://abc.go.com/primetime/greysanatomy for more information.

Bernadette Peters was last on Broadway in the acclaimed revival of Gypsy, for which she received a 2003 Tony Award nomination for her performance as Rose in the Sam Mendes-directed production. She won her two Tonys for her performances in Andrew Lloyd Webber's Song & Dance and Irving Berlin's Annie Get Your Gun, and she has also starred on Broadway in Mack & Mabel, On the Town, Sunday in the Park with George, The Goodbye Girl and the original production of Stephen Sondheim's Into the Woods. Peters' newest live recording, "Sondheim, Etc., Etc.—Bernadette Peters Live at Carnegie Hall (The Rest of It)," is available on the Angel Records label. Masterworks Broadway has also released a "Legends of Broadway" CD celebrating her theatrical career. Peters' screen credits are numerous.

The actress is also the author of the best-selling children's book "Broadway Barks," which benefits the charity of the same name.