MBP, that's the 5th season opener so that would have been 1971.
From Wiki: Sam Elliott as Dr. Doug Robert a.k.a. Lang (alternated with Lupus during Season 5 and appeared in one Season 6 episode)
From Wiki: Sam Elliott as Dr. Doug Robert a.k.a. Lang (alternated with Lupus during Season 5 and appeared in one Season 6 episode)




