Rafael Nadal discusses overcoming his own physical and mental health issues

Missing from this year's Olympics was tennis superstar Rafael Nadal. A foot injury forced him to sit the games out, but now he's aiming to score a record 21st Grand Slam title at the U.S. Open.

His road to the tournament starts in Washington, D.C., where he is back, wowing crowds with his forehand and incredible spin.  "I don't think today I am at my 100%," he told "CBS Evening News" anchor and managing editor Norah O'Donnell in an exclusive interview. "The goal is to be closer to that 100% the day I start the tournament."