If you want to know what’s on Joe Mauer’s mind, all you have to do is ask.

Not Joe. He’ll tell you that, jeez, it’s a nice day, and when you wake up, he’ll be gone.

You’ve got to ask Jake, Mauer’s big brother.

“Joe is a tough man to read, as you know,” Jake said.

When the Mauer parents were taking care of their kids, they evidently gave Joe all the protein and Jake all the personality. Jake, who is managing the Class A Cedar Rapids Kernels in the Twins’ farm system, isn’t surprised to see Joe settling into a second consecutive season of regular play and quiet efficiency that have distanced him from questions of durability that plagued him in 2011.

“I think he’s growing up,” Jake said.

Joe has graced the covers of sports sections since he was in high school. He has been a public figure for so long it’s easy to forget that he’s still a young man.

In April, Little Joe Mauer turned 30. Last winter, he got married, to Maddie Bisanz, a fellow alum of Cretin-Derham Hall. They are due to have twins in August. “I mean, twins?” Jake said. “Really? I think somebody has a plan.”

For most of his career, teammates knew Joe Mauer as the guy who slept until noon, avoided crowds and spent most of his spare time during the season in the trainer’s room or workout facility.

His life is about to change, and Jake senses a corresponding change in his brother. In terms of performance and durability, he might be on his way to his best season since he won the American League MVP award in 2009. For the second consecutive season, he’s playing virtually every day and ranking among baseball’s leaders in on-base percentage.

“Seeing him in spring training, he just seems really happy,” Jake said. “Maddie is a fantastic woman, very grounded, very family-oriented. Her family is just excellent. Our two families have fun together.

“I think Maddie has a lot to do with Joe being so at peace right now. He’s a little more outgoing than he has been in the past, and I think he’s a little more comfortable with where he’s at, not only professionally but in terms of his personal life. He just seems like he’s in a pretty good place.”

Jake and his other brother, Billy, have children. “It’ll be exciting in August when these twins come along,” Jake said. “[Joe] is great with my kids. He’s fantastic with Billy’s kids. He’s been comfortable around our kids for a long time. He’s going to be a great dad.

“But he’s not going to be able to sleep until noon anymore. I told him that. I said, ‘Get your sleep now, because life is about to change.’ We went down to spring training early and hung out a little bit, and he’s not sleeping ’til noon anymore. He’s starting to get up early. It’s been kind of fun to watch him change.”

Jake was standing behind the batting cage on a cool afternoon in Cedar Rapids, remembering what it was like to grow up in the baseball greenhouse that was St. Paul, home of Dave Winfield, Paul Molitor, Jack Morris and Joe Mauer.

Mauer remembers one Babe Ruth league game in St. Paul before Joe began attending high school. The home plate umpire was future Vikings center Matt Birk. The base umpire was future Phillies prospect Buzz Hannahan. The third baseman was future big-leaguer Jack Hannahan. Jake played short. Billy pitched. And little Joe got sent to right field.

“I remember none of us argued with the home plate ump that day,” Jake said.

Now Little Joe is 30, and about to become a father during one of those seasons that will solidify his standing as one of the best-hitting catchers in baseball history.

“He’s still bad at returning phone calls, but so am I, so I can’t throw rocks at a glass house,” Jake said. “As far as all the important things he has to take care of these days, he’s right on top of it. I think he’s really happy with where he’s at.”