You don’t do this when you’re undecided. You don’t do this when you’re coming back. You do it when you are absolutely certain this is your last day in the major leagues, when you want to go out the way you started, at the position you never wanted to vacate and missed every single day since you did.

That’s how it ended for Joe Mauer, on a chilly Sunday afternoon at Target Field, the perfect farewell to a St. Paul boy’s enchanted 15-year career.

In the top of the 9th inning, with no one on the field except the umpires, Mauer emerged from the Twins dugout in his old catching gear, the same old-style steel mask and multicolored Twins batting helmet he wore the last time he caught — Aug. 19, 2013. The gear sat in a bag in Mauer’s house until Saturday night, when Mauer dug it out and tried it on for the first time since suffering the concussion that necessitated his move to first base. The announced crowd of 30,144 had already greeted Mauer with standing ovations before all his at-bats, and the sight of Mauer the way most Twins fans remember him brought them back to their feet for the longest, loudest roar of the day.

It took every ounce of willpower Mauer possessed to fight back tears as he turned to all parts of the park, lifting his helmet in thanks, then patting his chest near his heart.

“To be able to go out there and have that moment, I’m thankful,” he said.

Mauer caught one pitch from reliever Matt Belisle — a ball — then departed, replaced by Chris Gimenez, who had as much trouble holding it together as Mauer.

“I was crying for the next three pitches before I locked it back in,” Gimenez said. Mauer was still in his catching gear when reliever Trevor May finished off the 5-4 victory over the White Sox, and he joined his teammates in the postgame handshake line for high-fives and hugs.

There was one more ovation as Mauer headed off the field, one more tip of the helmet. Then Mauer was shepherded to a postgame TV interview piped through the stadium loudspeakers. Even then Mauer remained noncommittal about 2019, a stance he repeated at a press conference a few minutes later.

“I’m not 100 percent sure, and like I said, I want to make sure I have time just to take a deep breath and really be behind that decision,” Mauer said while his wife Maddie, kindergarten-aged twin daughters Emily and Maren, parents Jake and Teresa, and assorted relatives and friends sat nearby. “But I couldn’t have asked for a better last day of the 2018 season, and I’m looking forward to just taking a breath and spending some time with my girls, my family, and we’ll go from there. But with the emotions running right now, I don’t want to say either way.”

The slim chance of Mauer returning, and Mauer’s own reluctance to be the center of attention, prevented Sunday from turning into a spectacle like the one in Queens on Saturday night, where Mets captain David Wright started his final game. At Target Field, there was no ceremony. No pomp. Mauer started at first base, led off and went 1-for-4. And the hit, a double in his final at-bat, combined all the things that made Mauer Mauer. He worked the count full. He drove the ball to left-center. And when left fielder Nicky Delmonico took his time to field it, Mauer hustled to second.

“Those are tough to script, and it was a moment that was meant to be for him to do it,” said manager Paul Molitor, another son of St. Paul. “I was getting yelled at by some of the fans when I didn’t pinch-run for him there, but we had other plans in mind.”

Mauer had to be talked into this final gesture, which his father, Jake, suggested to Maddie Mauer about a month ago. The idea worked its way through people in the Twins organization. Before Friday’s day-night double-header, bullpen catcher Nate Dammann — another St. Paul product and a Mauer confidant — and bench coach Derek Shelton took Mauer into equipment manager Rod McCormick’s office and broached it to him.

Mauer hesitated. Remember, two foul balls off his mask and helmet triggered his debilitating concussion; avoiding another was the whole point of moving to first base. What if it happened again?

“My first response was, `My wife might kill me if I go back there and they swing,’” Mauer said. So the Twins asked a favor of White Sox manager Rick Renteria: For that one pitch, can you tell your batter not to swing? Renteria said yes.

“I can’t thank Rick Renteria and the White Sox enough for agreeing and letting me have that moment,” Mauer said. “It meant a lot.”

Only a few people knew what was coming. “I wanted it to be a surprise to my Dad,” Mauer said. “We felt the less people who knew about it, the better.” Belisle learned a few days earlier when Mauer requested he pitch to him, a nod to the veteran Belisle’s character and professionalism. “When you’re asked to do something like that, it was just an honor that I cannot articulate well right now,” Belisle said. “I was a little taken away.”

Gimenez, equally honored, found out Sunday.

To further ensure secrecy, Mauer left his catching gear in the trunk of his car until the game started, when McCormick retrieved it. The bag stayed in the clubhouse, and that’s where Mauer dashed in the bottom of the eighth to put his gear on. Belisle delayed jogging in from the bullpen so Dammann could run to the dugout for a closer look.

Mauer was such a wreck that when Belisle finished warming up, his throw to second ended up in center field. Belisle was the same; he tried to throw a strike and couldn’t, even knowing batter Yoan Moncada was taking. And a day that began with Mauer’s girls running to greet him on the field for the national anthem, nearly knocking him backwards, ended in the most perfect way. Especially if this is the end.

“I think you guys saw how important that moment was for me, just to be able to put that gear back on,” Mauer said. “Given where we were as a team, I just couldn’t pass it up.”

One last time.