Both Robert Wagner and James Farentino would be on TV crime shows (combining action with comedy) during the 1980's: Wagner on Hart to Hart and Farentino on Blue Thunder.
A golf swing, especially a professional golf swing, is complicated therefore difficult for an actor to simply learn before filming (one of those things you either have, or don't); unlike some actors playing great golfers, Robert Wagner has a very good swing, so he probably was an avid golfer. (An example of a prime swing is Michael O'Keefe aka Danny Noonan in Caddyshack.) For this movie, Howard St. John and Guy Stockwell also had decent swings. The only bad swing from a supposed golf ace was Sean Garrison.
This movie is best known for not being very well known, since for decades it was very hard to find, never having a VHS, DVD or Blu Ray and only turning up occasionally on TV, including The Golf Channel.
In real life, Robert Wagner would later marry Jill St. John.