Minnesota Vikings running back Adrian Peterson, second from left, walks off the field following an NFL football training camp practice, Sunday, July 27, 2014, in Mankato, Minn. (AP Photo/Charlie ... more 
Minnesota Vikings running back Adrian Peterson, second from left, walks off the field following an NFL football training camp practice, Sunday, July 27, 2014, in Mankato, Minn. (AP Photo/Charlie Neibergall) less 
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Associated Press | Photo By Charlie Neibergall
Sun, Jul 27, 2014 1:30 PM EDT