Julianna Margulies and George Clooney courtesy Warner Bros.There's no series finale written and producers and cast aren't yet ready to sign off for good but if, as many predict, ER's County General closes its doors at the end of its upcoming 14th season, the NBC drama wants to lure back as many of its cast as it can. Noah Wyle (Dr. John Carter), who's popped in and out of the show for a number of years, is returning for multiple episodes, and there will be no running around in Africa this time. "He'll be in Chicago in the ER, interacting with all our people," executive producer David Zabel tells TVGuide.com. The doc is back to check out the Joshua Carter Center, a gift from his big-bucks family, as well as for a medical concern. In turn, ER is hoping to bring back Thandie Newton, who plays Carter's wife Kem.

Zabel says they've also talked to Gloria Reuben (as Jeannie Boulet) and Julianna Margulies (Carol Hathaway) about returns. "Julianna's doing a show now (midseason's Canterbury's Law), but we can always write a story that can shoot in a couple of days," the exec says. Also on their dream list and in the mix of story ideas being discussed: Eriq La Salle (Peter Benton), William H. Macy (David Morgenstern), and Sally Field and Danny Glover, who have had runs as Abby's mom and Pratt's dad. Fans might also expect visits from more recent exiles Laura Innes (Weaver) and Shane West (Ray).

But what about the most successful ER alum of all? "We're always thinking of ways to bring Dr. Ross back on the show," says Zabel with a laugh. "And now might be a good time, because I hear George [Clooney] needs the work."