Slated to guest star on "Grey's" are "Practice" cast members Kate Walsh, Audra McDonald and Taye Diggs. Former "Melrose Place" heartthrob Grant Show and "In Treatment" actress Melissa George are set to appear on the Feb. 12 episode of "Grey's," as well.
"Addison, Naomi and Sam rush the ailing Archer to Seattle Grace and reunite with old friends Derek and Mark to help save his life; meanwhile, Izzie employs her fellow doctors in a medical game designed to help teach the interns, and Owen runs into a significant someone from his past," ABC said in a news release.
Walsh plays Addison; McDonald plays Naomi; Diggs plays Sam; Show plays Archer -- Addison's brother; Patrick Dempsey plays Derek; Katherine Heigl plays Izzie; Kevin McKidd plays Owen; and Eric Dane plays Mark.
"Private Practice" is a spinoff of "Grey's."