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 Armand Assante Richard Elliot Guest Star Shohreh Aghdashloo Riza Kardatay Guest Star Zina Zaflow Nimet Kardatay Guest Star John Leguizamo Dr. Victor Clemente Guest Star Leland Orser Dr. Lucien Dubenko Guest Star Maury Sterling Dr. Nelson Guest Star Laura Cerón Nurse Chuny Marquez Guest Star Troy Evans Frank Martin Guest Star Yvette Freeman Nurse Haleh Adams Guest Star Evan Arnold Barry Sadler Guest Star Phil Abrams Rodney Guest Star Andie Bolt Hana Guest Star Christopher Chulack Executive Producer Michael Crichton Executive Producer David Zabel Executive Producer John Wells Executive Producer R. Scott Gemmill Executive Producer