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 Leland Orser Dr. Lucien Dubenko Guest Star Gina Ravera Dr. Bettina DeJesus Guest Star Mimi Kennedy Sergeant O'Malley Guest Star Laura Cerón Nurse Chuny Marquez Guest Star Troy Evans Frank Martin Guest Star Chloe Greenfield Sarah Riley Guest Star Marc Jablon Larry Weston Guest Star Joe Manganiello Officer Litchman Guest Star Gil McKinney Dr. Paul Grady Guest Star Natacha Roi Serena Lipnicki Guest Star Christopher Chulack Executive Producer Michael Crichton Executive Producer David Zabel Executive Producer John Wells Executive Producer R. Scott Gemmill Executive Producer