"This has probably been the most difficult decision that I've had to make in my career," Varitek said in a press conference from the club's spring training home field. "But the opportunity to be able to start and finish my Major League career in one place is why I'm standing here today."
Varitek, 39, broke into the majors in 1997 after being acquired with Derek Lowe in a trade that sent pitcher Heathcliff Slocum to Seattle. He finished as Boston's all-time leader in games caught with 1,488.
"As I walk away from this game, I can look at the man in the mirror and be proud that I gave everything I could to this game, this organization, my teammates," Varitek added.
"Jason has personified the rugged, aggressive, fiercely-competitive style of play that has characterized our club for more than a decade," Red Sox chairman Tom Werner said in a release. "His teammates knew it; our fans knew it, and opposing players knew it."
The switch-hitting backstop helped Boston end its 86-year World Series title drought in 2004 and led them to another championship three years later.
"I can probably now appreciate them more than I did when I was playing," Varitek noted. "Winning the World Series here was unbelievable."
Named the 18th captain in Red Sox history on December 24, 2004, the three-time All-Star caught a MLB-record four no-hitters.
"The uniqueness of (Jon) Lester's no-hitter and Clay's (Buchholz) no-hitter are going to be hard to forget," Varitek said.
Varitek, in a reduced role last year, hit just .221 in 68 games, and finished his career as a .256 hitter with 193 homers and 757 runs batted in. Only Carl Yastrzemski, Ted Williams and Jim Rice played longer in Boston without suiting up for another team.
"The hardest thing to do is to walk away from your teammates and what they've meant to you over the years," Varitek said.