San Francisco 49ers quarterback Colin Kaepernick warms up before the 2013 season opener.
Daniel Hartwig
CC BY 2.0
Derivative of <a href="//commons.wikimedia.org/wiki/File:Colin_Kaepernick_and_Kyle_Williams_warm_up.jpg" title="File:Colin Kaepernick and Kyle Williams warm up.jpg">file:Colin Kaepernick and Kyle Williams warm up.jpg</a>