Goran Visnjic Dr. Luka Kovac Actor Maura Tierney Abby Lockhart Actor Mekhi Phifer Dr. Gregory Pratt Actor Parminder Nagra Dr. Neela Rasgotra Actor Linda Cardellini Nurse Samantha Taggart Actor Shane West Actor Scott Grimes Dr. Archie Morris Actor Laura Innes Dr. Kerry Weaver Actor John Stamos Dr. Tony Gates Actor Paula Malcomson Meg Riley Guest Star Forest Whitaker Curtis Ames Guest Star Keith David Pastor Watkins Guest Star Kip Pardue Ben Parker Guest Star Lois Smith Gracie Guest Star Troy Evans Frank Martin Guest Star Chloe Greenfield Sarah Riley Guest Star Montae Russell Dwight Zadro Guest Star Jack Forbes Police Officer Guest Star Francis Guinan Police Negotiator Guest Star Christopher Chulack Executive Producer Michael Crichton Executive Producer David Zabel Executive Producer John Wells Executive Producer R. Scott Gemmill Executive Producer