Justin Gatlin Takes Verbal Swipe At Anti-Doping Crusader Lilly King

Although he made it look easy when he flashed across the finish line of his heat in the men's 100-meter sprint in just 10.01 seconds on Saturday, it continues to be a tumultuous road of return for one American sprinter. Justin Gatlin shrugged off criticism from swimmer Lilly King, who'd said athletes with a history of doping violations don't belong at the Olympics.

Thought to be the one sprinter able to give Usain Bolt, the fastest man in the world, a run for his money in the 100-meter event, Gatlin claimed to have no idea who King, his fellow Team USA teammate (and Olympic gold medalist), was. "I don't even know who Lilly King is," USA Today reports Gatlin said. "She does swimming, not track and field, so I'm not worried about that. I have come back and done what I need to do. I have worked hard just like everybody else, and I get tested like everybody else, and I am back here. I believe in the system."

As the Olympics unfold in Rio, King — whether she meant to or not — has become the anti-doping crusader of the 2016 Games. It began when King spoke out against officials' controversial decision to reinstate Russian swimmer Yulia Efimova despite her two previous doping violations. But King expanded her criticism of athletes with known doping violations — accidental or not — to include U.S. teammate Gatlin after defeating Efimova and winning the gold medal in the women's 100-meter breaststroke.

"I have to respect (track authorities') decision even if it is something I don't necessarily agree with," King reportedly told reporters in a post-race news conference. "Do I think people who have been caught for doping offenses should be on the team? No, they shouldn't. It should be set in stone. There should be no bouncing back and forth."

Gatlin tested positive for amphetamines in 2001 at the U.S. Junior Championships, though his subsequent ban was overturned after officials determined Gatlin was treating attention deficit disorder with the substance. In July 2006, two years after Gatlin won gold in the 2004 Olympics, the sprinter revealed the U.S. Anti-Doping Agency claimed he tested positive for "testosterone or its precursors." Although Gatlin denied having used any banned substance, he was banned from the sport or four years.

Now 34, Gatlin is reportedly the oldest American sprinter in more than 100 years to compete in the Olympic Games. Despite the controversy surrounding his participation, Gatlin has so far appeared well-suited to take on Bolt in the 100-meter sprint.