 Madlyn Rhue , who portrayed Lt. Marla McGivers , had previously worked with Montalbán in an episode of Bonanza in 1960 as his on @-@ screen wife ; she later appeared with him in a 1982 episode of Fantasy Island . Montalbán and Rhue also appeared in separate episodes of Roddenberry 's previous NBC television series , The Lieutenant ( 1963 – 1964 ) . Main cast member George Takei did not appear in " Space Seed " ; the character of Hikaru Sulu was replaced by Blaisdell Makee as Lt. Spinelli . It was the first of two appearances in Star Trek for Makee , who would return in the episode " The Changeling " as Lt. Singh . John Winston appeared for the second time as Lt. Kyle , and would go on to make nine further episodic appearances in that role . Following positive feedback from the producers and the network regarding James Doohan , " Space Seed " was the first episode to feature a more prominent role for his character , Chief Engineer Montgomery Scott . 
