Guy Williams appeared in five episodes towards the end of the fifth season as Ben's nephew, Will. Pernell Roberts wanted to leave the show and Williams was set to become a full time cast member in the sixth season. A storyline was written in which Adam Cartwright was to get married and leave the ranch. However, Roberts decided late in the season to stay for one more year so Will was written out of the show. The three other lead actors were unhappy with the Will storyline and would have rather continued without a fourth lead. When Roberts left after the sixth season, the series did continue with just the three leads.
Michael Landon and Guy Williams were in "I Was a Teenage Werewolf" previously.