Kate Walsh, Taye Diggs Sign to Grey's Anatomy Spinoff
02/22/2007 AT 03:00 PM EST
As first reported by the Wall Street Journal and confirmed to PEOPLE by ABC reps, the new show would star Kate Walsh, 39, who has become a fan favorite since she was introduced as the steely neonatal surgeon in a season-one cliffhanger.
Also on board: Taye Diggs, 36, who starred in UPN's Kevin Hill and ABC's Day Break, both from ABC TV Studio, which produces Grey's Anatomy.
ABC will test out the new show with a "back-door pilot," an expanded two-hour episode of Grey's, Reuters reports.
Diggs will appear in that episode, which has no set air date.
Grey's creator Shonda Rhimes is writing the episode, which, according to USA Today, will feature Walsh's character mulling an out-of-town job offer.
Should the spinoff go forward, Addison will most likely accept the offer; if it does not, she'll stay at Seattle Grace.