Michael Phelps is back in the pool, may have eye on Rio Olympics Michael Phelps has rejoined the U.S. drug testing program, the strongest signal yet that he's planning a comeback for the Rio Olympics. Phelps told the Associated Press on Thursday that "nothing is set in stone" though clearly he has enjoyed getting back into shape - he's down about 15 pounds - and working out with his former team at the North Baltimore Aquatic Club. "If I decide to keep going and swim again, then I'll compete," Phelps told the AP in an exclusive telephone interview from Minneapolis, where he is attending an Arena Grand Prix meet this weekend. "If I don't," he added, letting out a big laugh, "I guess I'll re-retire. Just don't compare me to Brett Favre. The U.S. Anti-Doping Agency said Phelps was among the athletes who underwent doping tests in the third quarter, the period ending Sept. He was tested twice. His former coach and close friend, Bob Bowman, said Phelps actually reentered the program near the end of the second quarter, but he wasn't tested and therefore wasn't listed that time in USADA's quarterly report. He would be eligible to compete again in March, according to Bowman. Each week, Phelps said, he's working out a couple of days in the pool, a couple of days in the weight room, and one or two days on his core training. By subjecting himself to drug testing, Phelps has given himself plenty of time to go through an entire season before the next major meet, the 2015 world championships in Russia, an important steppingstone to the Rio Games the following summer. 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, shattering the previous marks. He is best known for breaking Mark Spitz's record for a single Olympics by winning eight gold medals in Beijing in 2008. Phelps retired at age 27 after winning six more medals at last summer's London Olympics, adamant that he had no intention of competing again. He had long said his goal was to retire from swimming before he turned 30. He will be 31 at the time of the opening ceremony for the Rio Games. Canizares leads at Dubai, Stenson closes in on European money title Henrik Stenson strengthened his chances of winning the European money title, shooting a four-under 68 on Thursday that left the Swede two shots behind leader Alejandro Canizares of Spain after the first round of the season-ending World Tour Championship at Dubai, United Arab Emirates. Having already won the PGA Tour's FedEx Cup, Stenson also leads the Race to Dubai standings and was two shots ahead of nearest rival and playing partner Justin Rose of England. The points champion will receive $1 million from a $3.75-million bonus pool that counts on the final money list. In September, Stenson won the PGA Tour's season-ending Tour Championship to take the FedEx Cup title and $10-million bonus. Thailand's Kiradech Aphibarnrat and Australia's Marcus Fraser were tied for second at 67 on Jumeirah Golf Estates' Earth Course. Wales' Jamie Donaldson and Spain's Rafa Cabrera-Bello matched Stenson at 68. Thailand's Pornanong Phatlum took the first-round lead in the Lorena Ochoa Invitational, birdieing seven of the first 13 holes at Guadalajara Country Club in Mexico. The 23-year-old Phatlum, winless in five seasons on the LPGA Tour, dropped a stroke on the par-four 14th hole and finished with a six-under 66. Amy Yang was a stroke back, and fellow South Korean players Inbee Park and So Yeon Ryu were two shots back at 68 along with Sweden's Anna Nordqvist.