MINNEAPOLIS — Torii Hunter turns 40 this weekend. He’s been bracing for trouble.

Not from his body or mind, despite that daunting number for a professional athlete, but from his Minnesota Twins teammates.

“I don’t know what they’re going to do to me, but it doesn’t sound good because they keep saying, ‘When is it? When is it?”’ Hunter said. “When the guys start talking about your birthday a week out, they’re up to something. I’m scared.”

The special occasion is Saturday, and his concern ought to be limited to potential pranks. The way his season has gone, Hunter needn’t be worried about an age-related regression. Returning to his original team in a mentoring role has been energizing. He even said being back in Minnesota has made him feel younger.

The Twins, though, have been the ones experiencing the rejuvenation. Their 49-40 record was the second-best in the American League before the All-Star break, and Hunter’s presence has played a real part.

“He’s a very funny guy. He knows how to play the game. He’s a leader, you know?” Twins pitcher Ervin Santana said. “Everybody follows him, because he’s doing a lot of the right things.”

Signing Hunter to a one-year, $10.5 million contract gave the Twins a durable right fielder, a five-time All-Star who has played just as well if not better in his 30s than in his 20s. Another reason: Leadership for a team that averaged 96 losses over the last four seasons.

“The mentality that he brings in, that we’ve kind of embraced, of that short memory, forgetting about yesterday, forgetting about the game that happened an hour ago, that’s something that’s really helped us,” third baseman Trevor Plouffe said. “That’s kind of been the difference in the team from the years past.”

For outfielders Byron Buxton and Aaron Hicks, having another fellow former Twins first-round draft pick has been invaluable. Hunter’s impact has transcended his position group, too.

His affable, jokester nature has given the Twins clubhouse the kind of life it hadn’t had since, well, Hunter was here the last time a decade ago. He has initiated an elaborate ritual following victories by the Twins at home, featuring fog machines, laser lights and dancing in the middle of the room for the unofficial player of the game.

“I just go out there and do what I have to do that’s a part of me, and I always want to make guys around me better,” Hunter said.

Santana played with Hunter for five seasons with the Los Angeles Angels. He’d love to have a few more together.

“The way he’s treating himself, the way he’s eating, he can play four more years,” Santana said. “I tell him that all the time, and he’s like, ‘Stop.’ I’m like, ‘I’m right, dude.”’

Hunter is the second-oldest active position player in the majors, behind only Ichiro Suzuki, who at 41 is a part-timer for the Miami Marlins. Two of the seven 40-plus pitchers are currently on the disabled list.

His range in the outfield isn’t what it was when he was collecting nine Gold Glove awards with the Twins and Angels. His career-high errors total is five, established last year with the Detroit Tigers, and he had four by the All-Star break. His .312 on-base percentage projects to the third-worst of his 19 major league seasons.

Still, he has 14 home runs, a pace that would give him 25, the most since he went deep 28 times in his last year with the Twins in 2007. He’s driving in runs at the same rate he has in that span, too. Last Saturday against the Tigers, he hit a two-run homer into the third deck at Target Field, a place only a few right-handed sluggers have reached. In the ninth inning that night, he made a tumbling catch of a sinking line drive.

“I’ve been really, really pleased,” manager Paul Molitor said, citing aloud his estimates of Hunter’s statistics. “It’s just a lot of production. Good at-bats. When you hit him second, he knows what to do there as far as taking pitches and using the whole field. And he can still ambush a fastball.”

Hunter gave his performance a C-plus midseason grade. He’s just as determined to keep satisfaction from saturating the team, with a road trip to Oakland and Los Angeles facing the Twins after the break and the Kansas City Royals still leading the AL Central division by a healthy margin. That the Twins have even found themselves in this conversation, though, has a lot to do with their ageless leader.

“When you’re producing,” Molitor said, “it’s a lot easier to lead.”