THERE are days – Mother’s Day, for instance – when the walls and the fortresses Anthony Sullivan has constructed inside his heart become a little more vulnerable than usual, a little more exposed. Images fill his eyes then. Fragments of old memories. And feelings that lie dormant the rest of the time.

“It’s then,” he says, “that I guess it would be nice to have a regular family. Mom. Dad. Brothers. Sisters. It hits me, and then it passes. And then I get back to my life again.”

Anthony Sullivan’s teammates on the St. John’s baseball team never see those moments, but they probably wouldn’t know to look for them, either. To them, Sullivan is just another cog in the Red Storm machine, a 5-11, 175-pound sophomore pitcher with some life in his right arm, with some big baseball ambitions and some bigger dreams, a Red Sox fan from Arlington, Mass., whose thin strip of a beard conjures the look David Ortiz made famous last October.

“I’m a punk, and they know it,” Sullivan says, laughing. “Ask any of them and they’ll tell you I can really be a piece of work.”

To a man, they would agree. But, then, to a man, they don’t really know much about Anthony Sullivan’s backstory, because it’s not something he often talks about.

So they might be shocked to discover that, despite the heavy Boston brogue, he was born in Rego Park, less than four miles northwest of the St. John’s Jamaica campus. Or that he was born John Anthony Caicedo on July 2, 1984, son of Juan Antonio Caicedo and Diane Sullivan.

Or that, at age 8, with his father nowhere to be found, he woke up one midnight inside the family home in Arlington, Mass., to find his baby brother, Joseph, crying in the nursery and his mother passed out on the bedroom floor. Or that three years later, four undercover Boston cops stormed the family apartment and arrested his father, and the two haven’t spoken since. Or that a year after that, Joseph died suddenly, a victim of Sudden Infant Death Syndrome.

Or that three years after that, while vacationing in Maine with his aunt and uncle, he received the most shattering phone call of all: Diane had lost one last battle with her demons, overdosed on heroin. Even at 15, he’d known that call was coming sooner or later. He’d seen his mother struggle with the drug his whole life.

“I’ve seen a lot. I’ve lived a lot,” Sullivan says. “I guess you could say I grew up fairly street smart.” He could have gone another way, of course. He had every excuse built in, after all. But he also had an aunt and uncle, Lisa and Steven Sullivan, who took him in, gave him a semblance or normalcy that had been so absent for so long, even gave him two young cousins who became surrogate brothers to him. And he had that live right arm. That, he knew, would be his ticket to a better life.

“I’m not gonna lie to you,” Sullivan says. “They say college isn’t for everyone, and it isn’t really for me. The only reason I’m here is because it’s my opportunity to play baseball. I do what I have to do, but everything in my mind is geared toward getting better and getting drafted. That’s the dream.” He will likely get his chance, sooner or later, thanks to a fastball that can hit 94 on the gun, thanks to a first-rate change-up and a curveball he’s worked hard to refine. His coach, Ed Blankmeyer, wishes Sullivan would ease his foot off the throttle a little, spend more time in the cozy cocoon St. John’s offers. But he understands.

“He’s definitely a draftable prospect,” Blankmeyer says. “He has terrific talent. I happen to think he could use the structured environment of college baseball for another year or two, but that’s a decision that’s going to be his to make, if he gets the chance to make it.”

There’s little question where Sullivan’s mind is. Ask him when the draft is, he says, smiling, “Thirty-three days and counting.” Ask him if he’d like to be taken by his hometown Sox, he shrugs it off, but then adds, “I do know they have the 23rd and 26th picks,” then laughs some more. If he goes, it won’t be that high. But a guy can dream.

“I guess if I’ve learned anything, it’s that you have to take advantage of whatever breaks you can get,” he says. “You better make the most of them. But it’s good to have goals.

For now, he has several. Today, he’ll take the mound against Notre Dame in an important Big East game at The Ballpark at St. John’s, and for most college baseball players that would be enough. Sullivan has a few others in mind. Someday, he’d like to speak to his father again, though he has little idea where to start. It’s believed Juan Antonio was deported to Colombia, though Anthony has never been able to confirm that, or whether he’s even still alive.

“Not to have a relationship, or anything like that,” Anthony Sullivan says. “Just to have a talk. I want him to know I’m all right.”

Amazing as it sounds, he is. Maybe today he’ll have one of those moments that arrive from time to time. It is Mother’s Day, after all. But his aunt and uncle will be there, at The Ballpark. His teammates will be there. There will be a full lineup of Fighting Irish players to pitch to. All things considered, it’s not a terrible place to be.