 The appearance of Lenard was originally suggested by Gene Roddenberry as an alternative to an appearance by Leonard Nimoy, as it was suspected that it would be too expensive to have the latter actor reprise the role of Spock on television. Roddenberry had previously barred references to Star Trek: The Original Series in The Next Generation; the inclusion of Sarek in his namesake episode, along with a mention of Spock, was seen by the crew of The Next Generation as a breakthrough, allowing them to reference The Original Series more freely in the future. Sarek's failing health was intended to be a reference to the declining health of Roddenberry. "Sarek" received Nielsen ratings of 10.6 percent; it was praised by critics, who lauded the performances of both Lenard and Stewart.
