NFL stars James Harrison, Clay Matthews and Julius Peppers can start the regular season without having the specter of a league investigation over whether they used performance-enhancing drugs hanging over their heads. The NFL cleared all three players on Wednesday, saying there was ''no credible evidence'' the players were guilty of any of the claims made in a documentary by Al-Jazeera America in January. The league threatened Harrison, Matthews, Peppers and free agent Mike Neal with indefinite suspensions if they did not meet with investigators. More...