1905 Giants
History Enthusiast
Sandy Koufax did not throw one bullpen session when he pitched for the Dodgers, mostly because of a destroyed elbow, but he was able to throw more because he did not waste his the tearing of his ligaments on worthless bullpen sessions.
According to "Sandy Koufax" by Jane Leavy. Koufax did indeed throw in the bullpen. At least once over 100 pitches.