"I go out to the mound, and he looks at me," Montero said Sunday. "[He said] 'We have to quit throwing sliders to that guy.' I looked up and said, 'You have to quit hanging it.'"
Then, Montero turned and walked back to the plate, and realized what he had done.
"After I did it, I thought I was going to get sent down," Montero said. "It didn't happen -- after the game, he came to my locker and said I was right."
There are times when Montero is wrong. He remembered a game against the Pirates when Andrew McCutchen homered off a young D-backs pitcher, hitting a changeup.
"It hurts me when they give up a run -- I take it personally," Montero said.
Credit former big league catcher Bill Plummer with teaching Montero to focus on catching. Now, the Cubs are benefiting.
Is Montero always right at home, too?
"My wife has to be right," Montero said. "Happy wife, happy life."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.