David Kohan Creator, Executive Producer Max Mutchnick Creator, Executive Producer Eric McCormack Will Truman Actor Debra Messing Grace Adler Actor Sean Hayes Jack McFarland Actor Megan Mullally Karen Walker Actor Shelley Morrison Rosario Salazar Actor Jack Black Dr. Isaac Hershberg Guest Star Stephanie Faracy Eva Guest Star Laura Kightlinger Nurse Sheila Guest Star Gerald Downey Clark Guest Star James Burrows Executive Producer, Director Jeff Greenstein Executive Producer Bill Wrubel Writer Alex Herschlag Executive Producer Jhoni Marchinko Executive Producer