I'm sure I read somewhere that Cabot was supposed to play that part, but due to his lung and throat cancer he could not. His last film was Diamonds Are Forever which was made in 1971, like The Cowboys. You would expect Wayne's best friend to be played by either Cabot or Ward Bond.
I hadn't heard this, but Bruce cabot was supposed to have the role of the
Pinkerton man in The Train Robbers, but couldn't due to his illness.
