Baltimore Ravens center Matt Birk, bottom, plays with his children on the Mercedes-Benz Superdome field after an NFL Super Bowl XLVII walkthrough on Saturday, Feb. 2, 2013, in New Orlea

 

              Baltimore Ravens center Matt Birk, bottom, plays with his children on the Mercedes-Benz Superdome field after an NFL Super Bowl XLVII walkthrough on Saturday, Feb. 2, 2013, in New Orlea
Baltimore Ravens center Matt Birk, bottom, plays with his children on the Mercedes-Benz Superdome field after an NFL Super Bowl XLVII walkthrough on Saturday, Feb. 2, 2013, in New Orleans. The Ravens face the San Francisco 49ers in Super Bowl XLVII on Sunday. (AP Photo/Patrick Semansky)