It’s a Wednesday during the offseason, a rare day off. Michael Fulmer is playing golf.

He’s slowly getting better, he says by phone from the first tee at KickingBird Golf Club in Edmond, Oklahoma, but still not any good.

“It’s getting there,” he said.

His golf game certainly wasn’t there in spring training, when Tigers teammate Justin Verlander would spot him 13 or 15 strokes and still beat him.

“All the time,” Fulmer said.

Back then he was just a promising pitching prospect with an outside chance to make the team. He spoke softly and worked hard. But a sensational season later, the right-hander is the American League’s Rookie of the Year. And perhaps as soon as this upcoming season, he’ll become the successor to Verlander as staff ace.

“It’s still hard to wrap my head around a little,” he said. “It was a fun season.”

Ask how his offseason is going and you find out that for Fulmer, there isn’t much of an offseason.

A day earlier he was hard at work. He was in backyards around the Oklahoma City area digging ditches and changing sewer lines. Replacing old Orangeburg pipes with new PVC pipes. In basements exchanging water heaters, in kitchens replacing sinks and faucets, in bathrooms fixing leaky toilets.

These days Fulmer works as a part-time plumber.

“I don’t cut him any slack,” said Larry Wright, Fulmer’s boss at Cyrus Wright Plumbing, a small, long-standing family business in Yukon, Oklahoma. “He digs ditches and gets dirty, and does whatever needs to be done.”

It’s Fulmer’s second offseason working with Wright, who is the uncle of one of Fulmer’s good friends. He came aboard last year in a pinch, when Wright’s son – also a plumber – went off on another job.

“He called me and I said, ‘All right, we’ll see how it goes from here,’ ” Fulmer said. “And I’m still doing it so it’s fun.”

In his rookie plumbing season, Wright said, Fulmer picked up the common-sense side of things quickly, like how to get from Point A to Point B in a job. Other things, like learning the different equipment, names of the parts and tools, came with time.

“It took him a little while for him to know what everything was called and when I asked for something,” Wright said.

One thing Fulmer didn’t have a problem with was the physical work, and answering the bell a few mornings a week at 8 a.m. for what usually stretched into 10-hour days. At 6-foot-3, 210 pounds, he has become Wright’s right-hand man for the more strenuous side of the job on big projects, like digging those six-foot ditches.

“Generally, it’s hard,” Wright said. “When he’s working with me, he’s usually digging in or working on jackhammers. It’s pretty physical work, but he’s a great worker. He always wants to know more, he wants to know what we’re doing, why we’re doing it, and he never complains.”

Fulmer picked up plumbing last offseason as the latest odd job in his procareer. In the first couple of offseasons of his minor league career, starting when he was a farmhand with the Mets, he worked at golf courses around the Oklahoma City area, herding golf carts and behind the counter in the pro shop.

There he picked up golf, taking tips from some of the head pros. Now, after balancing both side jobs last offseason, he’s focused on plumbing, which serves as a starting point for his offseason workout regimen, which he began a short while ago.

“It’s a different kind of workout,” Fulmer said. “Digging out of six-foot ditches all the time and shoveling quite a bit. So it’s a different type of workout, and it helps before I start working out.”

Said Wright: “That’s what I tell him. He should be paying me.”

On any given weekday, one of the most up-and-coming pitchers in baseball can be found in backyards, basements, kitchens and bathrooms, serving a working-class job for customers who have yet to recognize the youngster who has won every rookie award.

“He’s gone unrecognized,” Wright said. “He doesn’t carry himself like a big-time person. He’s down to earth, so I think unless you’re a Tigers fan or know him personally, I don’t think you’d recognize him.”