BOSTON — Red Sox reliever Trevor Kelley proudly has his daughter’s 3D ultrasound photo displayed in his locker at Fenway Park. She’s due Oct. 14.

The first-time father plans to spend this winter as a stay-at-home dad after he worked multiple jobs each offseason since the Red Sox drafted him in the 36th round (1,071 overall) in 2015 out of UNC.

“My schedule last year, at least four times a week I would wake up at 6 and I’d leave for construction until about 3 o’clock, then go work out," Kelley told MassLive.com. “Then I would (teach) baseball lessons. Then I would ref beach volleyball at night. I’d get home at like 10, 11 o’clock at night, wake up and do the same thing the next day."

Kelley received only a $1,000 signing bonus out of UNC. Most minor leaguers who receive small bonuses must work offseason jobs because of low minor league salaries.

But Kelley will be able to spend a lot of time with his growing family this offseason after Boston added him to the 40-man roster July 2. He made his major league debut that evening vs. the Blue Jays in Toronto.

The Red Sox optioned him back to Triple-A Pawtucket just two days later (July 4). But as a member of the 40-man roster, Kelley was required to receive at least the minimum minor league salary for 40-man members with at least one day of major league service time. The minimum is $90,400 or $594.74 before taxes for each day in the minors.

The major league minimum is $555,000 before taxes. It calculates to $2,983.87 each day a player is on the major league roster.

“Making it to the big leagues in July was a dream come true," Kelley said. “Now getting back here in September is life-changing, what it does for me and my wife right now.”

Kelley isn’t the only Red Sox player who has worked multiple offseason jobs and is seeing his hard work rewarded with major league money.

“Working every day is just part of it,” Kelley said. “In the minor leagues, it’s part of it.”

Minor league salaries often are disturbingly low — and players lost minimum wage protection with the “Save America’s Pastime Act.”

The major league minimum salary of $2,983.87 per day is more than many minor league players earn in a month. Minor league salaries can be as low as $1,160 per month (before taxes and clubhouse dues) for Class-A affiliate players and as low as $2,150 a month before dues and taxes for first-year Triple-A players, ESPN.com’s Jeff Passan reported.

Minor and major league players receive pay checks only during the baseball season; not in the offseason.

“It’s less than minimum wage in most states,” Red Sox rookie reliever Josh Taylor said. “It really is a grind. In the minor leagues if you didn’t sign for (big bonus) money, you’re definitely having to work in the offseason to get by. Just about every minor leaguer works."

Red Sox righty Josh Smith also described 40-man roster money as “life-changing."

“Because when you’re in the minor leagues, you’re making $10,000 a year,” Smith said.

‘Now I’ll be able to work out at a baseball facility’

Taylor emerged as one of Boston’s top relievers in 2019, posting a 2.98 ERA in 45 ⅓ innings.

The Phillies signed the lefty as an undrafted free agent Aug. 12, 2014, after he spent that summer pitching in the Northwoods League, a collegiate baseball league. He never received a lucrative signing bonus. The Phoenix native worked customer service at the Phoenix Convention Center during offseasons.

"I’d work out on the docks and help with the trucks; like back them in and everything,” Taylor said.

The Red Sox added him to their 40-man roster last November. He made his major league debut May 29. He has spent all but three days on the 25-man roster since then.

“I finally won’t have to work in an offseason, which is nice,” Taylor said. “I can actually afford to work out at a nicer, actual facility this offseason. Usually, I was working every day. So after work, I’d go to LA Fitness and get my workout in. But now I’ll be able to work out at a baseball facility and get everything done there and have more focus on getting ready for spring training.”

Kelley also will train more this offseason.

“I’ve had to grind in the offseason and sacrifice a whole lot of time that could go to baseball,” Kelley said. "When it comes to spring training, that’s when I really lock in and make up ground that I lost in the offseason.”

Taylor said the salary increase “definitely helps you move forward in life.”

“Even just getting put on the (40-man) roster, even if you are in the minor leagues, you’re making at least five times, six times as much as you made in the minor leagues,” Taylor said.

A minor leaguer player on the 40-man roster who is under contract for the first time and has no major league service time receives a minimum salary of $45,300.

Red Sox 22-year-old pitching prospect Denyi Reyes is an example. The Red Sox added him to the 40-man roster last November to protect him from December’s Rule 5 Draft. He has yet to make his major league debut. He spent the entire 2019 season at Double-A Portland where he earned at least $45,300.

“Minor leaguers, that’s a long offseason,” Red Sox reliever Heath Hembree said. “You’ve got to cover all of September if you’re not in the big leagues. Spring training, you have to kind of make it through February. Even big league spring training, you get the big league meal money, which is nice. It’s a nice pay raise just being in big league spring training as a minor leaguer.

“It’s completely different being on the minor league side," Hembree added.

Hembree who appeared in 256 minor league games, is earning $1.3125 million in 2019, his first year of salary arbitration.

“On my end now, I’ve done OK,” he said. “Still, during the offseason money is going out and nothing’s coming in."

‘I made $10,000 a year playing baseball’

Josh Smith received only a $1,000 signing bonus like Kelley did.

He signed with the Reds on June 18, 2010, after they drafted him in the 21st round (637th overall) that year. He lacked negotiating power as a fifth-year senior out of Lipscomb University in Nashville, Tenn.

“It was take $1,000 bucks or go to the workforce," Smith said. “I took my $1,000. After taxes— I still have my stub, actually, hanging up. I have a little fishing room where I tie lines and I have some baseball achievements and stuff like that. I saved my stub; $653."

His $1,000 bonus dropped to $653 after taxes.

Smith made more money during the offseason than during the baseball season until he became a member of a 40-man roster. The Reds selected his contract from Triple A in 2015.

“I would get up 5. I would be at the gym by 5:45," Smith said. "I’d be at work by 8. I’d get off about 5 or 6. It was construction. So it just kind of depended on if the job was a deadline that week or whatever; we’d have to stay late. And then I’d give pitching lessons, usually from 6-10. I’d go home and go to bed. That was my offseason for four months.”

Smith, who no longer has to work during the offseason, also pointed out insurance in the majors is much better than in the minors.

He closed on his first house in 2018, approximately seven and a half years after signing his first professional contract.

“I made $10,000 a year playing baseball,” Smith said. “So you can’t buy a house. So I never did. I lived with my parents."

He became a minor league free agent after the 2017 season. That delayed the purchase of a home until after he signed with the Mariners in March 2018.

“I was blessed enough to make enough money where we were able to buy a house,' Smith said. “It was right around the time we had our son. And my wife, she works full-time. So that obviously helps.”

‘Just about to everybody that’s a lot of money’

Red Sox manager Alex Cora has received some criticism for a 21-man pitching staff this September. Having that many pitchers is just not real baseball, right?

The September active roster will reduce from as many as 40 players to a 28-player maximum in 2020. Good, right?

Not if you’re an underpaid minor leaguer hoping for an opportunity to showcase your talent in the majors and earn a month salary that would provide some financial security.

A player earning the major league minimum will receive $86,532 (before taxes) if he’s on an active roster for all 29 days this September.

“Just about to everybody that’s a lot of money,” Yankees’ Mike Tauchman said. “It’s a big deal. I think it’s a good way to reward somebody financially that’s had a really good year in the minor leagues.”

Hembree said, “I was a product of the September call-up in 2013 with the Giants. Having those couple of paychecks going into the offseason was nice. I’m not going to lie. The pay obviously is nice. But just kind of had the opportunity to be able to be a part of the big league atmosphere and just get your feet wet, get a little bit more experience.”

The Red Sox added lefty Robby Scott to the 40-man roster in September 2016. Boston had purchased his contract from Yuma of the independent North American League in 2011.

He stood out in the minor leagues and received a chance to show what he could do in the majors while also earning some real money that September. Scenarios like this won’t happen as often starting in 2020.

Ryan Dull, who pitched for the Yankees this year, made his major league debut for the Athletics as a September call-up in 2015.

“It can be life-changing, especially for a guy who has had to work for everything," Dull said.

“Low-round draft picks, it can change everything,” Dull added. “They might not have to work that extra job in the offseason. They save it right, they might be able to afford a down payment in the future. It gives them a little bit more of a sigh of relief, especially guys with families already that have been struggling in the minors."

Dull finished his degree at UNC Asheville after signing.

“So I had a place to stay," Dull said. “But some of the guys I work out with ... would work in the factories and shipping just like moving boxes. They’d work until the wee hours of the morning.”