Retired swimmer Michael Phelps makes move to qualify for 2016 Olympics

Michael Phelps has rejoined the U.S. drug-testing program, the strongest sign yet that he's returning for the 2016 Rio Olympics.

The U.S. Anti-Doping Agency said Phelps was among the athletes who underwent doping tests in the third quarter, the period ending Sept. 30. He was tested twice.

That coincides with Phelps' longtime coach, Bob Bowman, telling The Associated Press last month the swimming great had resumed occasional training at the North Baltimore Aquatic Club. Bowman characterized it more as an effort to get in shape than launch a comeback.

FINA, the world governing body for swimming, requires an athlete to be tested for at least nine months before taking part in sanctioned events. Phelps is the winningest and most decorated athlete in Olympic history. He captured 18 gold medals and 22 medals overall at the last three Summer Games. -- AP