– Zack Granite first noticed a gray hair on his temple when he was 14. Pretty soon there was another one, and another, and before long, he was the most mature looking teenager at Tottenville High School on Staten Island.

“I’m an old soul, I guess,” Granite said. “But girls liked it, so I was OK with it.”

These days, he walks around the Twins clubhouse with a subtle salt-and-pepper shade that makes him looks like a veteran, and not the 24-year-old rookie he is. And it’s not just his hair that makes him seem older; it’s his playing style, too.

Granite, the Twins’ 14th-round pick in 2013, is a speed-first table-setter, a player who would have been right at home racing around the bases in the dead-ball era, or perhaps for a turf team in the 1970s. He has been a professional for only four years, only 337 games, and already has swiped 102 bases. Of those, 56 came last summer at Class AA Chattanooga — and no player in the minor leagues had more.

“Fifty-six, it’s a big number, I don’t care what level you’re at,” Twins manager Paul Molitor said. “It shows no fear.”

Granite had a near-permanent green light from Lookouts manager Doug Mientkiewicz, on the notion that there’s no better way to learn.

“Doug and Sammy [minor league baserunning coordinator Sam Perlozzo] would talk to me when I got thrown out, about why I made a mistake. You’re not learning if you don’t go,” said Granite, who was thrown out 14 times for a success rate of 80 percent. “I went a lot, sometimes not on the right pitch, but I got better. I ran as much as I could, and it helped us win games.”

Granite would like to do the same for the Twins, and Molitor is intrigued by having another player with extraordinary speed, to go with Byron Buxton, on his roster. The Twins have a quartet of veteran outfielders hoping to capture a spot as a utility outfielder, but Granite is making a case to stay in-house.

“He’s one guy I was looking forward to watching play,” Molitor said of Granite, a .282 hitter with 102 steals in 140 attempts over 337 minor league games. “He’s coming off a really good year with a lot of people speaking really highly of him. I like those kind of players. There’s a place for those guys.”

Like Buxton, Granite is a terrific defensive center fielder, though he doesn’t have the power that Buxton possesses. He hit four home runs for the Lookouts last season, and “I wasn’t expecting that,” he said with a laugh. He also hit .295, walked as often as he struck out, and won the Sherry Robertson Award as Twins Minor League Player of the Year.

And his instinct for the game is getting attention, too. Monday, Granite was on second base when Ben Paulsen hit a sharp line drive. Rays left fielder Cade Gotta came racing in and tried to dive for the ball before catching it on a short hop. Granite had to hold up to make sure the ball wasn’t caught, but then suddenly sped up when it bounded a few feet out of Gotta’s glove, scoring easily.

“My favorite part about the play today was that he made the decision himself. He came into third, he didn’t look for help, he saw the bobble and kicked it into gear,” Molitor said. “That was good instincts. [He has] strike zone knowledge, defensive awareness, he’s thrown the ball well, he’s gone and got it.”

All that, and he hasn’t even stolen a base yet.

“I don’t care who’s on the mound, I think I can hit anybody. I’ve got the confidence to be here,” Granite said. “Playing scared, that’s not my game. I believe I belong, so hopefully somebody else does, too.”