FORT MYERS, Fla. -- Jason Varitek spent 15 seasons as the stoic center of the Boston Red Sox, with an icy stare that never blinked and an iron jaw that never quivered.

The toughness and tenacity that defined his career and galvanized the Red Sox back to the top of the baseball world finally gave way on Thursday night, when the Captain bid farewell.

With his wife and three daughters by his side, and his parents and dozens of teammates watching from just a few feet away, an emotional Varitek officially announced his retirement.

"My teammates," Varitek said, his voice shaking and his eyes welling, are "what I'm going to miss most. The hardest thing to do is to walk away from your teammates and what they've meant to you over the years."

If Dustin Pedroia is the heart of the Red Sox and David Ortiz is the soul, Varitek was the steel spine that held everything together.

He caught four no-hitters, played in three All-Star games, won two championship rings and had one memorable run-in with Yankees star Alex Rodriguez that will endear him to Boston sports fans forever.

"You have not only been our captain, you have been our rock," Red Sox chairman Tom Werner said. "You have personified the rugged, aggressive, fiercely competitive style of play that has characterized our club during your tenure."

The Red Sox acquired Varitek and Derek Lowe in a lopsided trade with Seattle for Heathcliff Slocumb in 1997. The catcher spent the next 14 seasons helping turn the Sox from a seemingly cursed franchise that tortured its fans by choking in big moments to one of the dominant teams of this century.

"I'm probably a little biased," ace pitcher Josh Beckett said. "I'm sure there's guys on other teams who have guys on their teams who they say the same thing about. Even watching him from afar, you could see other guys on other teams have that respect for Jason and he deserved it."

And his fingerprints were everywhere.

He was the welcoming confidante when a teammate needed advice, the stern voice of reason when a pitcher wanted to shake him off in a big spot and the aggressive bodyguard when an opponent dared challenge them.

The moment everyone will remember came in 2004 against the hated Yankees, when Rodriguez chafed after being hit by a pitch from Bronson Arroyo. As Rodriguez cursed at Arroyo, Varitek shoved his mitt into A-Rod's face, sparking a bench-clearing brawl.

"I was just being a teammate," he said.

During his speech, Varitek thanked a long list of people who helped him along the way, from his Little League coaches to the baby sitters who watched his three daughters, his family, the clubhouse staff and, of course, bullpen coach Gary Tuck.

"My decision to retire wasn't something I took lightly in any sense of the word, nor do I want to do it more than once," he said. "But the opportunity to start and finish my major league career in one place meant more to me, and is why I'm standing here today."

The Red Sox offered the 39-year-old a chance to come to camp on a minor league deal, and Varitek briefly looked at other teams as well. But in the end, the chance to play his entire career with one team won out.

"That meant a lot," his father, Joe, said. "He said, 'I'm a Red Sox. And once a Sox, always a Sox. That's big with him."

The decision didn't come quickly. He labored over it for months while agent Scott Boras prodded him to come to a conclusion.

Boston Red Sox catcher and captain Jason Varitek wipes away a tear during his retirement announcement in Fort Myers, Fla., Thursday. AP Photo/Alan Diaz

"I still trained and tried to get myself ready," Varitek said. "I love being able to play. I love the competition on the field, the chess game behind the plate. It's not easy."

Boras hinted that there may have been other options for him, both this winter and in previous seasons. But winning the World Series in 2004 and 2007 helped Varitek know for sure that he didn't want to go anywhere else.

"When you lead a pitching staff and you've set a tone for the organization and you watch players, he just really identified with this team," Boras said. "And that's what his peers knew him as, a Boston Red Sox. So it was something that was more than a uniform or a job or a place."

Perhaps fittingly, Varitek is leaving the game at the same time as longtime Yankees catcher Jorge Posada. The two became fixtures behind the plate in the late 1990s, on opposite sides of the most heated rivalry in baseball, and spent the next decade and a half as the steadying forces behind their star-studded teams.

"I'll tell you what, Jason was unbelievable," said David Wells, who pitched for both Boston and New York. "He was a guy who came prepared every day. It's just a shame that I didn't have him catch me longer because he's almost right there with Jorge. Jorge is my guy, and will always be there, but just way the Jorge prepared, he did his homework and Jason was the same way."

Varitek said Posada reached out to him this week after the news broke of his decision.

"You see a lot of games and you butt heads quite a bit," Varitek said. "His job is to make sure we get out, my job is to make sure they get out and our job is to make sure each other gets out. But you can respect what you have to do behind the plate and the little things."

It's hard to imagine Varitek without that No. 33 jersey with the "C" on the left shoulder draped over his chiseled frame. Hard to picture the Red Sox clubhouse without Varitek sitting at a chair in front of his locker with enormous ice bags on his shoulders, knees and elbow.

"As I walk away from this game, I can look in the mirror and be proud that I gave everything I could to this game, to this organization, to my teammates," Varitek said.

As he stood at the podium in front of home plate at JetBlue Park, Boston's shiny new spring training home with the replica Green Monster in left field, Varitek was asked how difficult it will be for him to walk into a ballpark for the first time as a non-player.

"I just did," he said.

Information from The Associated Press was used in this report.