PORT ST. LUCIE, Fla. -- Two offseasons ago, Mets catching instructor Glenn Sherlock called Hayden Senger during the offseason, looking to chat. Senger picked up but told his longtime coach he’d need to call back.

“Why?” Sherlock asked him.

“I’m working,” Senger replied, before returning to the supermarket floor.

For the past two years, Senger has spent his winters stocking shelves at a Whole Foods near his Nashville-area home. This sort of thing used to be common even among well-established ballplayers, but as salaries have ballooned and workouts have become more all-consuming, relatively few still maintain second jobs.

Senger is one of the exceptions. A 27-year-old whom the Mets selected in the 24th round -- a round that doesn’t even exist anymore -- of the 2018 Draft, Senger has spent the last seven years climbing the organization’s Minor League ladder. He never received a life-changing Draft bonus. His paychecks have not made him wealthy. Three years ago, Minor League salaries ranged as low as $4,800 per season. When the union negotiated a significant bump for 2023, the Triple-A salary minimum rose to $35,800.

Asked why he took a job at a supermarket, Senger shrugged. “I needed the money,” he replied.

Four days per week, Senger wakes up around 5 a.m., reports to Whole Foods an hour later and stocks product until noon. Typically, Senger moves groceries from U-Boat carts onto the sales floor, lugging all sorts of items around the store. Often, he’ll pick up an extra shift on a Friday or Saturday. More than once, a coworker has asked him for an autograph.

“He’s definitely one of the best workers I’ve ever had,” Senger’s manager, TJ Sanfilippo, said in a telephone interview. “He comes in, he says hello, and then he just gets to work. I don’t have to say anything. … I’ll see him making a huge dent into grocery just in the six hours he’s there. It’s almost like he works 10 hours per day in the results he shows.”

The most challenging items for Senger are large water jugs, which can weigh more than 40 pounds apiece. By the time he finishes heaving those onto shelves, Senger has often broken a sweat.

“My Apple Watch, I almost hit my calorie goal by 10 o’clock every day,” Senger said. “It’s, like, functional strength.”

When his shift ends, Senger heads to the gym or the batting cage for a more sport-specific workout, before finally returning home. Part of the reason why he gravitated to Whole Foods, Senger said, was because it gave him evenings free with his wife. If he had accepted a more common offseason job as, say, a youth baseball instructor, he’d have little time left with her.

“It’s a pretty good schedule,” he said.

In baseball circles, what makes Senger’s story unique is not just the fact that he has a second job, nor that he’s spent more than a quarter of his life slogging through the Minors. It’s that Senger, through all of it, suddenly finds himself with a realistic chance at cracking the Major Leagues. When starting catcher Francisco Alvarez suffered a hamate bone fracture that will sideline him for Opening Day, it resulted in a promotion for backup Luis Torrens. That, in turn, opened a roster spot for one of three hopefuls: Jakson Reetz, Chris Williams, and Senger.

Reetz, whom the Mets signed to a Minor League contract early last offseason, is the only one of that group with big league experience. Williams, another Minors signing, has the most robust offensive resume of the bunch.

But Senger offers his own advantages, including a defensive skillset that multiple scouts praised as elite. Senger’s throwing and framing both grade out as significantly above-average. He blocks balls expertly. Given his years in the organization, Senger also possesses as much knowledge of Mets pitchers as any other catcher on staff.`

“He takes defense very seriously, and he works at it,” Sherlock said. “No matter how well he does, he’s still out there every day trying to get better.”

Sanfilippo, Senger’s Whole Foods manager, sees similar qualities in him. But here’s the catch: if Senger makes the Mets’ Opening Day roster, he’ll earn a pro-rated portion of the Major League minimum -- this year, $760,000 -- for as long as he’s in The Show. That’s more than $4,400 per day.

Asked if an extended run in the Majors might prompt him to quit his side job, Senger hesitated. Before Senger left for Spring Training, Sanfilippo told him he’s welcome back at Whole Foods anytime.

“I’m pretty superstitious,” Senger said, grinning. “I told my boss it’s possible I come back if I make it, but I didn’t make any promises. So we’ll have to see about that.”