Graham takes over Parenthood from Tierney

Former E.R. star Tierney was forced to pull out of the upcoming series in July (09) after she was diagnosed with the disease, bringing shooting to a halt.

Helen Hunt had been tipped to pick up where Tierney left off, but Graham has been chosen as the star’s replacement.

The Bad Santa star will portray a single mother of two teenage kids who moves in with her parents – the same character Tierney played in the pilot episode.

Craig T. Nelson, Dax Shepard and Bonnie Bedelia are also part of the ensemble cast.