Cesar Tordesillas

Baltimore Ravens center Matt Birk has announced his retirement, ending a stellar 15-year career with a Super Bowl ring.

"I certainly didn't plan on playing football for 15 years," Birk told the team's official website. "So kind of not having a plan has worked out for me so far, so I'm going to stick with it."

"To cap it with a Super Bowl win, that's a great thing," added Birk, who finished his career with 112 straight starts, the longest active streaks among centers.

A sixth-round pick out of Harvard, Birk was selected to six Pro Bowls and was named to the USA Today's All-Decade team (2000s).

Birk said didn't make his decision until Thursday afternoon, and he spoke to coach John Harbaugh and general manager Ozzie Newsome about it.

"Just ultimately I followed my heart," Birk said. "I just kind of waited a couple weeks for it to settle and kept coming back to this being the right decision for me and my family."

Birk's decision was expected as the Ravens drafted his eventual replacement, Gino Gradkowski, in last year's draft. The Ravens save $2 million on the salary cap with Birk no longer on the roster.

Birk won the NFL's Walter Payton Man of the Year award in 2011 for his community service. He is planning to donate his brain to science to aid research on sports concussions.

Baltimore Ravens Center Matt Birk Retires After 15 Seasons - NFL 2013