Maura Tierney is undergoing a "medical evaluation," a statement from NBC said Friday.
Shooting on her new series Parenthood has been postponed "for eight weeks due to medical evaluation that valued cast member Maura Tierney is undergoing," the statement read. "We are unable to release further details and ask that you respect her privacy at this time."
Tierney, 44, starred on ER from 1999 to 2009.
Ironically, one of Tierney's costars from the iconic medical drama, Deezer D is hospitalized and will undergo heart surgery next Tuesday.
Parenthood, which also stars Peter Krause, Erika Christensen and Dax Shepard, was to premiere in September. It's now tentatively pushed back until 2010.