Gilbert Flores/Celebrity Photo
02/22/2007 AT 03:00 PM EST
Meredith Grey may soon have Addison Shepherd out of her hair for good: ABC is considering a Grey's Anatomy
spinoff focusing on Dr. McDreamy's ex wife.
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,
Diggs will appear in that episode, which has no set air date.
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.