Unofficial list of free agents
Check out this unofficial list of the 2013 NFL restricted and unrestricted free agents, which includes Greg Jennings. More ...
That decision is now made. The longtime center announced his retirement at Battle Grove Elementary School in Baltimore on Friday. Birk, 36, never missed a game in his four seasons with the Ravens, serving as the anchor of Baltimore's offensive line.
"I've enjoyed playing football. But as much as playing football, I've enjoyed doing this," Birk said, referring to community service with children.
When asked by a student why he was retiring, Birk replied: "I'm old. I've got six kids. ... It's time to do something else."
Birk walks away despite two years remaining on a three-year, $8.525 million deal signed last March. According to The Baltimore Sun, Birk's retirement will clear $2.05 million from Baltimore's salary cap.