Joe Mauer is a three-time batting champion, so he wasn’t often fooled by a pitch. But he never saw this one coming.

Cretin-Derham Hall High School, Mauer’s alma mater in St. Paul, invited him to speak to a student assembly Tuesday in the new athletic center that bears his name, “kind of like a Twins Caravan event — just answer some questions here and there, shake some hands,” Mauer said.

When he showed up at Joe Mauer Field House, however, he found his extended family and Twins owner Jim Pohlad among the student body, too, and together they watched a videotape of Minnesota Gov. Mark Dayton formally declaring Tuesday as Joe Mauer Day in his home state.

Then Twins Hall of Famers Bert Blyleven, Tom Kelly, Tony Oliva and Kent Hrbek took the stage in unison, with Hrbek making a surprise announcement: Mauer’s No. 7 will soon join their own numbers on the left-field facade at Target Field, retired forever at a ceremony next summer. When Mauer finally took the podium, his response was vintage Mauer: “Wow.”

“I’m still kind of in shock,” Mauer said of the new honor, which puts his 7 in the company of that foursome, along with Kirby Puckett, Harmon Killebrew, Rod Carew and Jackie Robinson, among numbers retired by the Twins. “… Now when I take my kids to the game, and see No. 7 up there, it’ll probably put a smile on my face every time I see that.”

A lot of people were smiling Tuesday at the symmetry of receiving the team’s highest honor just a few feet from the spot where he signed his first professional contract with the Twins, back in 2001.

“It’s an amazing thing, that Joe’s able to start his career in this building, basically, and to be able to come back and have his number retired,” said Twins owner Jim Pohlad, whose father, Carl, signed Mauer after the Twins made him the No. 1 pick in the draft. “It’s a huge commemoration of his career.”

The Twins wasted no time in bestowing the honor, Pohlad said, making the announcement barely more than a month after Mauer’s retirement. But they wanted to surprise Mauer with the inevitable decision, “and I think we did that. … He seems very happy.”

He is, Mauer said of his post-baseball life, though he’s a little sleep-deprived, too, thanks to his 1-month-old son, already nicknamed Chip. He’s enjoying his usual winter break from baseball, and warily contemplating the withdrawals he expects to arrive with the spring.

“I know I’m going to miss it. I’m going to miss stepping into the box against the best in the world every night,” Mauer said. “I’ll miss that when I’m 60 years old.”

To combat any impulse to pull on a baseball uniform, though, he’s begun wearing basketball shorts, and is considering hockey pads, too. He’s given up baseball, but hasn’t retired from sports.

“I got into a pickup game here on Sundays,” Mauer said. “A buddy called me up and said, ‘Hey, what are you doing on Sunday mornings? I want you on my team.’ ”

Because of restrictions in his contract, “I hadn’t played in a pickup basketball game in 18 years,” Mauer said. And it showed, he said.

“It was not pretty. But last Sunday was the second week, and it’s getting better,” he said. “I definitely didn’t go in the paint. I was facilitating.”

He plans to do some facilitating of a different type next year, expanding the operations of the Joe Mauer Foundation, now that he has the time. He’s already deeply involved in helping children at the Gillette Children’s Hospital in St. Paul, and he wants to continue the Mauer and Friends Kids Classic, an annual benefit for the hospital.

And then?

Mauer might drop by training camp next spring, but only to say hello, he said. He’s intrigued by helping prospects learn the game as a part-time coach, a role that Pohlad said the team will invite him to do. Mauer’s family owns auto dealerships and other enterprises, and that’s a possibility, too.

“Joe has a lot of options,” said Twins President Dave St. Peter. “I could see him getting involved in some businesses. I know he’s going to stay involved in the community. He could do a lot of different things in retirement, and the Twins and baseball are just one of those options.”

Hmm. Might he someday want to be the one declaring special days for deserving Minnesotans?

“I don’t think I’ll do that,” said not-yet-Gov. Mauer. “But you never know.”