The Boston Red Sox are sticking to a long-range blueprint for success and relying on 21-year-old shortstop Xander Bogaerts as a critical cog in defense of their World Series crown.

No less an authority than Boston second baseman Dustin Pedroia welcomes the prospect of entering the 2014 campaign with rookie Bogaerts as his double-play partner.

“His ability is unbelievable,” Pedroia told reporters at the Red Sox spring training headquarters in Fort Myers, Fla. “He has the willingness to learn and get better every day. He wants to be great, too.”

The Red Sox were unexpected champions last season, capping a brilliant decade of baseball with their third World Series title in 10 years after going 86 years without one.

That Boston team was built on a transfusion of free agent veterans including Shane Victorino, Mike Napoli and reliever Koji Uehara, who banded together under a battle cry of “Boston Strong,” in memory of the Boston Marathon victims, to complete a wild, worst-to-first ride to the title.

Chemistry among the players, and between the team and a city rocked by the fatal bombings at the Boston Marathon, seemed to lift the beard-growing Red Sox to the delight of Fenway Park fans who had endured a last-place 2012 finish in the AL East.

Should Boston prevail again in their highly competitive division, it could be Bogaerts, just starting his career, and new center fielder Grady Sizemore, striving to revive his, as the new difference-makers.

Bogaerts, one of MLB’s top-rated prospects, filled a late-season role in Boston’s improbable run, showing maturity well beyond his years as he manned third base in Game 5 of the League Championship Series and stayed in the lineup all the way through their six-game, World Series triumph over St. Louis.

Unperturbed by the harsh spotlight and enormous pressure, Bogaerts displayed poise and patience and skill at the plate as he batted .296 in 12 postseason games after playing in 18 regular season games following his debut in August as the fifth player from Aruba to reach the major leagues.

Bogaerts gave a glimpse of his confident approach before the season when he helped the Netherlands advance to the semifinals of the World Baseball Classic in San Francisco before falling to eventual champions Dominican Republic.

Bogaerts’s emergence had a domino effect. It allowed Boston to trade slick-fielding Jose Iglesias to the Tigers as part of a three-team deal that brought them White Sox pitcher Jake Peavy.

It also led the Red Sox to let 2012 regular shortstop Stephen Drew depart as a free agent.

Bogaerts will be manning a youthful left side of the infield alongside slugging third baseman Will Middlebrooks, 24, who has played parts of the last two seasons at Fenway.

Center field will also have a new inhabitant as stolen base king Jacoby Ellsbury left as a free agent to join the Yankees.

That key spot on the diamond might be manned by another rookie in Jackie Bradley Jr., or by Sizemore, who was one of MLB’s most dynamic players but has not played a major league game since 2011 and not had a full season since 2008 because of serious knee and back injuries.

Manager John Farrell has been closely monitoring Sizemore, 31, and the former Indians All-Star has been playing with his old abandon, diving for catches and racing around the bases.

“The most encouraging thing is he has not hit the proverbial wall where we’ve bumped up against the limits and have to pull back. We haven’t reached that yet, which is all extremely positive,” Farrell told reporters.

“Every piece of feedback from the medical staff has been positive with the end thought that he’ll become an everyday player,” added Farrell, who named Sizemore the starting center fielder Friday.

Catcher A.J. Pierzynski has taken over for Jarrod Saltalamacchia at catcher in the only other major change on the Red Sox roster, which will again be sparked by veteran slugger David Ortiz.

A great season of pitching formed the backbone of Boston’s success story last year and most of the crew responsible for the league’s sixth best ERA will be back.

As will Japan’s Uehara, who as the third option after season-ending injuries to Boston’s first two choices as closer, saved the bullpen.

“I think we have a lot of guys with a lot of personal pride who are working every day and not looking too far ahead,” said starting pitcher John Lackey. “I think that makes it easy motivation.”