FORT MYERS, Fla. – Of Boston’s “Big 3″ prospects, Marcelo Mayer may be the one with the most to prove this year, and that’s fine by him.

He hates to lose. Always has.

It was actually a bit of a problem back in the day.

“I always was super competitive as a kid and I love to win,” the shortstop told the Herald. “I would cry when I’d lose in school recess, stuff like that. I had anger issues! I’d want to fight the kids if I lost in soccer.”

“That’s definitely toned down now, I’m way more chill, but it used to be really bad. I was like, wanting to throw hands if I lost,” he added with a chuckle.

Despite coming from a baseball family – his father and uncle were on the 1981 Nogales High School baseball team that won the Arizona state championship, and another relative played in the minor leagues and Mexican League – he’s always felt the need to prove himself. That’s why, even though he’s in big-league camp this year and coming off missing significant time the last two seasons due to injuries, this spring training doesn’t feel too different.

“Obviously as sports fans you want to see your players on the field,” Mayer said. “I know that hasn’t been the case for me, but I think that’s just a product of the way that I play. I think I play the game extremely hard and I want them to know that I always give it my all.

“I think the way that I play and the way that I go about my business stays the same; I always play with a chip on my shoulder. I always have played extremely hard, and that’s never going to change. That’s just the way I play baseball. But I’m definitely excited to be on this side to show everybody here what I could do.”

Being in big-league camp as a top prospect can be intimidating. In many ways baseball is an old-fashioned game that values tradition. Some veteran players hold faster to the hierarchy and make prospects and younger players run the gauntlet, but Mayer said that hasn’t been the case in the Red Sox clubhouse.

“Being around the guys, (I’m) getting more and more comfortable every day,” he said. “They’re all super cool. I’m learning from Trevor (Story), all the veterans. I have a lot of resources, super lucky.”

One veteran, in particular, has blown Mayer away.

“It’s sick,” he said of Alex Bregman joining the Red Sox. “He’s super intense in the way he goes about his business and just the way that he wants to win. And he knows in order to win, we all need to be performing really well, so he cares a lot about our development, us as people.”

After signing his three-year, $120 million contract late last week, the veteran infielder wasted no time forging relationships with the top prospects.

“The first day he was here he literally sat with us for like, two hours during lunch,” Mayer said. “He was just getting to know us, wanting to know what we were about, helping us. He doesn’t have to do that. He just signed for what, $120 million, and for him to do that and just talk shop with us, talk baseball, get to know us was really cool.”

Mayer also said he wasn’t bothered by first baseman Triston Casas’ recent comments about how the “Big 3” should begin the season together in Triple-A while the big-league roster gets figured out. Casas is only entering his third full season in the majors, but he has a track record of making an effort to get to know prospects and offering himself as a resource, and he and Mayer have a solid relationship.

“To me, my job is in between the lines and I love the work I’m getting here, I’m learning a lot,” Mayer said. “Tristan and I are good. He said what he said, and we move on.”

Being a top prospect can be daunting, especially in a high-pressure market like Boston when there’s been little success at the big-league level over the last half-decade. So it helps that Mayer isn’t on the journey alone. Between climbing the rankings, their joint Triple-A promotion, and rooming together last season and at spring training, he and top outfield prospect Roman Anthony have become an inseparable duo.

“I think we share the same personality,” Mayer said. “We were both the young kids in the clubhouse, so that kind of bonded us right away, and then we both admired the way that we worked and the way that we showed our talents on the field. He was that person for me, I was that person for him, and ever since then we’ve been really close.

“We are great buddies, and we share the same goal, which is to make it to Fenway and hopefully win a lot of World Series,” Mayer said. “To go up the ranks with somebody like that and have him be super close to you, and now being in big-league camp together, it just makes everything that much better. I played with Roman all last year, we’re super-close, we talked all offseason, now he’s in the locker next to me in big-league camp. It makes everything that much more comfortable.”

One of the things that impresses him the most about Anthony is his maturity. Mayer only turned 22 in December, but Anthony won’t be 21 until May.

“I could honestly talk about Roman for days. The way he carries himself on and off the field, it’s super pro,” Mayer said. “You wouldn’t think that he’s 20 right now and can’t even have a drink.

“It’s not normal for a 20-year-old to be in big-league camp by any means, and he’s fitting in. It looks like he’s been in three big-league camps already. The way he is around the clubhouse, with the older guys and the vets, he looks comfortable here.”

“I think when he gets up (to the majors), sooner rather than later, he’s going to play his heart out, play super hard,” Mayer said. “In the box he’s one of the most polished hitters I’ve seen in a while. And he’s 20, so I can only imagine when he’s 25. He has extreme potential, he knows it, he recognizes it, and he works really hard.”

The pair spends their free time going to the beach, cooking (steak is a favorite), and watching television and movies. They watched several romcoms last season – Anthony liked ‘How To Lose a Guy in 10 Days’ the best – and Mayer has a new list of movies for this year.

“We need to watch (‘Fever Pitch’), but first we need to watch ‘Grease,’ because he’s never seen ‘Grease,’ which is criminal,” Mayer said. “If you haven’t seen ‘Grease,’ you’re a problem. One of the best movies ever.”

“Is that the one with the singing and stuff in it?” Anthony asked.

“Yes, it’s the one with the singing and stuff in it,” Mayer replied. He then began singing the opening line of one of the musical’s most iconic songs, “Summer lovin’, had me a blast!”

Or in their case, spring training, having a blast.