When Herzog coached third base for the Mets in the early 1960s, he said Stengel used to write him motivational notes calling him "a great leader" and a future big-league manager.
"My high school teachers would have died if they had heard him say that," Herzog said. "But the big thing is he knew."
So to honor his mentor, Herzog spent a good portion of his Hall of Fame induction speech Sunday by telling stories about his time with Stengel.
They first met when Herzog was in spring training with the Yankees as a player in 1954, but their relationship took off when Herzog joined Stengel's coaching staff a decade later with the Mets.
Nearly 50 years later, Herzog still is convinced that Stengel took an interest in him only because Stengel thought he was the grandson of Stengel's former teammate, Buck Herzog.
"I'm sure of that, and I never told him any different," Herzog said. "He would say, 'How is Granddad?' I'd say, 'Oh, hell, he's great.' "
Herzog said they used to talk a lot, with Stengel dispensing advice about how to be a manager.
"He said when you manage, you hire good coaches," Herzog said. "Don't worry about this coach taking your job because, he said, if you don't own the club or die on the job, you're going to get fired, anyway."
Stengel also gave Herzog advice about how to deal with the media, saying he should always ask how much time the reporter needed before the first question was asked. Then, Stengel said, when Herzog responded to the first question, he should continue talking until the time was up to avoid further questions.
"He had his own language and it took me hours sometimes to figure him out," Herzog said. "They thought he was a clown when they brought him back to New York, but Casey was an outstanding teacher."
Herzog, 78, now can point to himself - and the Hall of Fame line on his resume - as proof. He went 1,281-1,125 with the Cardinals, Royals, Angels and Rangers.
With the Cardinals, he focused on speed and defense, which became known as "Whitey Ball." That brand of baseball led to a world championship in 1982 and National League pennants in 1985 and 1987.
All weekend, Herzog joked that he was sick of being the center of attention, saying he couldn't wait to go back to his daily lifestyle centered on fishing. But he nearly broke down as he closed his speech, describing his induction into the Hall of Fame as "going to heaven before you die."