On Saturday, Brad Lang, a Marine veteran who lost both legs in an explosion while on patrol in Afghanistan in 2011, will announce a draft pick for the Carolina Panthers. He was selected by the NFL to represent the new league that will play in Chicago, Los Angeles, Phoenix and Kansas City, Missouri.  Then Lang will continue preparation for the wheelchair version of America’s most popular sport. Disabled Sports USA, with funding from the NFL and the Bob Woodruff Foundation, plans to launch a league in the fall.