Phelps dives back in the pool next week
Michael Phelps speaks at a press conference after competing in the Men's 50m Freestyle prelim during day two of the Arena Grand Prix at the Skyline Aquatic Center on April 25, 2014 in Mesa, Arizona - by Christian Petersen
Phelps and fellow Olympic champions Ryan Lochte and Allison Schmitt are among those slated to compete in the May 15-18 US Grand Prix event in Charlotte.
After taking four gold medals and two silvers at the 2012 London Olympics, Phelps took 20 months away from swimming, but announced three weeks ago that he would be making a comeback.
Phelps was a runner-up to Lochte in the 100m butterfly at a US Grand Prix meet in Mesa, Arizona, last month and excited fans with the idea that he might take the plunge in quest of a fifth Olympics in 2016 at Rio de Janeiro.
Phelps and his coach, Bob Bowman, have been coy about whether or not Rio is in their plans, but the Charlotte meet and another June 19-22 in Santa Clara, California, are the best chances Phelps will have to post qualifying times for the US championships in August in Irvine, California.
That event serves as the American qualifying meet for next year's world championships in Russia, the last major full global showdown in the pool before Rio.
Phelps won an unprecedented eight gold medals at the 2008 Beijing Olympics, but such endurance tests and ironman efforts are likely not what the latest comeback will feature.
Phelps is expected to swim more shorter events, as he did with the 50m freestyle and 100 fly in Arizona last month. He comes off a high-altitude training camp into the Charlotte meet.