"I said, 'Look, this is going to be different. You're going to be in a fishbowl,'" Don said. "And he is. The camera goes to him every time something happens. As a general manager, he's in the box up there, nobody ever sees him. I've told him that was going to happen."
In the Jennings' family, father truly knows best. Don Jennings, 77, is still the defensive coordinator for the football team at UMS-Wright Preparatory School in Mobile, Ala. And he's still steering his children in the right direction.
In 1977-78, Don was the defensive coordinator at Fairhope High School, located near Mobile. Dan Jennings, a standout quarterback and defensive back, missed much of his senior season due to a knee injury. However, intense rehab, including running bleachers at the urging of his father, got him strong enough to throw a two-hit shutout to open the baseball season that spring.
Don coached the baseball team when Dan was a senior.
"My dad, by far, has been the biggest influence, the biggest foundation in my life," Dan Jennings said. "Probably the biggest thing I can say is, he's tough, but fair. When he needed to be tough, he was tough."
Before accepting the Marlins' offer to replace Mike Redmond as manager, Dan adhered to a long-time family motto: "You can't win if you're afraid to lose."
Dan heard that expression his whole life.
"It's just one of the things you pick up in coaching," Don said. "You hear things like that and pass it around to your children."
The switch from front office executive to manager with no previous coaching experience has created plenty of commotion throughout the game. Jennings, with 31 years in scouting and evaluating, accepted the challenge because he felt it was the right move at the time.
"After I got to thinking about it, I could tell in his voice he sounded like he wanted to do it," Don said. "The next day I called him back. I said, 'If that's what you want to do, do it. What better way to learn more about the game than to be involved in it with the players?'"
Thrown immediately into the managerial fire, Jennings is aiming to lead the Marlins back into contention. It's not an easy task, but nothing has come easy for the former general manager.
"The first night on TV, I was watching Dan," Don said. "I'd never seen anybody chew bubble gum as fast as he chewed bubble gum that night. He looked like the most nervous individual in the world."
By contrast, Don recalls the calm, collected style of Hall of Fame manager Joe Torre.
"I'd watch Joe Torre. He'd sit in the dugout, his leg crossed one over the other, no expression on his face," Don said. "If a relief pitcher gives up a grand slam home run and loses the ball game, no expression.
"The next night, the opposite happens. His guy hits a home run. No expression. It's not easy to be that way."
Growing pains are part of the job. But Don quickly reminds, just because his son lacked previous managing experience doesn't mean he isn't up to the job.
"He knows baseball," Don said. "He's been around it all his life. Obviously, he got to be a general manager because he knows what he's doing. He's there."
In the world of coaching and managing, there are no guarantees.
"Like I told him, 'It's not that you stand in line the longest, and it's now you're turn to get up front.' You've got to get there, whatever method it takes," Don said. "I revert that back to coaching. A lot of times, a coach stays on the staff 15 years. Then, the head coach leaves, and they don't get the job. Somebody else comes in."
When watching his son a month into the job, Don sees a more comfortable-looking Marlins manager.
"From what I've seen on TV lately," Don said. "I've actually seen him sitting down in the dugout. And not chewing gum like he was."