 Sterling Hayden (qv) was originally supposed to play the knife  expert, Britt. Hayden dropped out for unknown reasons, so  John Sturges (qv) sent out an extensive casting call.  Robert Vaughn (I) (qv) (Lee) recommended old schoolmate and friend  James Coburn (qv) for the role. Vaughn and Coburn helped each  other get roles throughout the rest of Coburns life.