...audiences could only see him as Mr. Roarke

https://www.metv.com/stories/ricardo-montalb-n-nearly-refused-the-role-of-khan-on-star-trek-because-he-was-afraid-audiences-could-only-see-him-as-mr-roarke

"I thought, 'My God, audiences are going to laugh at me if I sound exactly like Roarke.'"