"Dancing with the Stars" professional dancer Mark Ballas was reportedly injured while performing on tour and will take time off to recover. The 22-year-old dancer announced Saturday night during a show in Los Angeles that he had suffered a groin injury and will need to take "a couple of weeks" off to heal, People magazine reports. Ballas grimaced in pain as he apologized to the Staples Center crowd for not being able to give his all, while still managing ...