Dallas Cowboys defensive end Greg Hardy on the sidelines against the New England Patriots. Christian Peterson /Getty images hide caption

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Former Pittsburgh Steelers defensive lineman L.C. Greenwood waving to fans in 2006. He died Sunday at the age of 67. Stephen M. Gross /UPI /Landov hide caption

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Denver Broncos quarterback Tim Tebow celebrates after beating the Pittsburgh Steelers 29-23 in overtime of an NFL wild card playoff football game on Sunday, (Jan. 8, 2012). Chris Schneider/AP hide caption

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