SOUTH PORTLAND — Baseball’s hot stove season is all about organizations signing the apple of their eye and celebrating that union with a long-term commitment.

Jackie Bradley Jr., touted as the bedrock of the Boston Red Sox outfield for the foreseeable future, can relate on multiple levels.

“I signed a pretty long contract,” Bradley said. “A lifelong contract.”

Don’t get too excited, Sox fans. Bradley is talking about that legally binding plunge that men of a certain age have taken by the millions throughout recorded history. He married Erin Helring in the offseason.

It’s another sign of the advanced maturity that kept Bradley, 23, ahead of the curve throughout his collegiate career at South Carolina and on his rapid ascent through the Sox’ minor-league system.

Boston brass and fans alike hope that translates to a breakthrough year as the World Series champions attempt to fill the void left by Jacoby Ellsbury’s departure to the vilified New York Yankees.

Bradley won’t engage in any presumptuous, it’s-my-job-to-lose talk.

“Every day is a competition,” Bradley said earlier this month in an interview prior to the Portland Sea Dogs’ annual Hot Stove Dinner. “There’s always somebody out there trying to take your spot. You go in with that mindset. That’s all you can really do every single day is go and compete, and the rest is history. See what happens.”

It’s wisdom that comes from experience, his tender age notwithstanding.

Bradley opened the fateful season as Boston’s starting left fielder at Yankee Stadium. In the type of performance that would become a trademark of the relentless 2013 Sox, Bradley drew three walks, scored two runs, drove in another and took away a couple of certain hits with his glove in a one-sided victory.

Instead of emerging as one of the dominant personalities on a team destined for immortality, however, Bradley languished through what was the most humbling season of his baseball life.

The rookie never settled into a groove. Multiple times, he was the odd-man-out to make room for one of Boston’s eventual playoff heroes.

After scuffling to a 3-for-31 start, Bradley was optioned to Triple-A Pawtucket on April 19 when David Ortiz returned from the disabled list.

“It was different in that aspect. I didn’t know what was going to happen,” Bradley said. “I was just bouncing around, up and down, and there were a lot of adjustments. That’s the way the game is. You have to make adjustments, and the strong survive.”

Bradley returned to Boston on May 29. Less than a week later, he belted his first major-league home run against the Texas Rangers.

But just as quickly, Bradley was returned to the minors June 8 after one of Shane Victorino’s stints on the DL. He was recalled for six more days in July and again once rosters opened up in September.

The numbers: .189, 3 HR, 10 RBIs.

It was a far cry from the production that made Bradley the 2010 College World Series MVP, the 40th overall pick in the 2011 draft or the 2012 defensive player of the year in the Sox system.

Just don’t call it a lost season.

“Experience. You’ve got to see what it’s like,” Bradley said. “You’re just learning from the veterans, trying to pick up on certain things. The do’s and the don’ts. The ins and the outs of a particular situation. What you do on the field. How you conduct yourself as a professional.”

Oh, and there was that small matter of earning a World Series ring in year one.

“It was special to be around. You see the passion and the camaraderie,” Bradley said. “Obviously you can’t put a formula on camaraderie or how a team bonds together. ‘We’re going to win ‘x’ number of games.’ It doesn’t work like that, but I kind of got that feeling when I was up there that everybody was focused on one goal, and that was winning the World Series.”

Bradley was drafted by a franchise in the grip of an identity crisis. The season-ending tailspin that led to Terry Francona’s firing in 2011 and the 2012 bottoming-out under Bobby Valentine’s watch left Boston entering ’13 with experts’ lowest expectations for the team in more than a decade.

His most valuable lesson of the rookie year, aside from learning to weather slumps and disappointments, was observing how Ortiz, Victorino and other veteran leaders kept the Sox on task.

“The character, the leaders on the team, letting nobody get sidetracked from what the team wanted to accomplish,” Bradley said. “That was from day one. Winning the championship was the main goal.”

Baseball was Bradley’s dream from an early age.

When adults asked what was back-up plan, “baseball” was the answer. His reasoning: “Nobody asks a doctor what his back-up plan is.”

He has made the journey look easy, at times, but there have been enough speed bumps along the way that 2013 didn’t shake Bradley to the core.

“Even the good years, you’re still going to have those humbling times,” he said. “They might not be as noticeable because people see the numbers and say, ‘Oh, you had a great year.’ I guess it’s more noticeable when your numbers aren’t as good as expected.

“It’s just a humbling sport in general. You’re going to have times when you don’t even feel like a baseball player. That’s the way it is. You’ve just got to enjoy it and have fun and go out there every single day knowing that you put in the work.”

Bradley doesn’t get specific about his year-to-year goals. Getting into the major-league lineup and staying there, presumably, are among them.

Team aspirations? Those roll off the tongue.

Though he’s allowed only one wedding ring, there is no limit to the professional jewelry Bradley and his teammates covet.

“It’s a new year, but we are defending champions,” he said. “We take pride in what we do. If you have a good year, we as ballplayers feel like we can do better. You’re obviously not going to do better than a world championship, but you set that same goal.”