USC QB Sam Darnold retooling throwing motion

Quarterback Sam Darnold fires a pass during USC’s spring game at the Los Angeles Memorial Coliseum in Los Angeles on April 15, 2017. (Photo by Ed Crisostomo, Los Angeles Daily News/SCNG)Quarterback Sam Darnold fires a pass during USC’s spring game at the Los Angeles Memorial Coliseum in Los Angeles on April 15, 2017. (Photo by Ed Crisostomo, Los Angeles Daily News/SCNG)USC quarterback Sam Darnold fires a pass during USC’s spring football game at the Coliseum in April 2016. (Pho