Article Photos: RG3 sustains concussion; Polamalu re-injures calf 1/3

  Kansas City Chiefs quarterback Matt Cassel (7) walks off the field with trainers during the second half of an NFL football game against the Baltimore Ravens at Arrowhead Stadium in Kansas City, Mo., Sunday, Oct. 7, 2012. The Ravens defeated the Chiefs 9-6. (AP Photo/Colin E. Braley)