LOS ANGELES - Olympic superstar Michael Phelps said he is "sick and tired of just getting whooped" as he tries to get his sputtering comeback on track at the Santa Clara Pro Swim.
Also headlining the action will be 20-year-old fellow-American Missy Franklin, who will compete as a professional for the first time, with the Rio Games next summer.
Phelps may boast 18 Olympic gold medals but at his last outing in May, he finished outside the top two in all his events.
NOT THERE YET
He's had a very good training cycle since he came back in November. The one thing he hasn't done is swim well in a meet yet.
- Bob Bowman, Michael Phelps' coach
This was something that had not happened to him since he competed at the Sydney Olympics as a 15-year-old.
Phelps will test himself in five events in California, with three of them - the 200m individual medley, 200m backstroke and 100m freestyle - all falling tomorrow.
He is hoping for a solid showing against elite swimmers before the August US championships in Texas.
He will sit out the World Championships in Russia at the same time as part of a sanction for a drink-driving incident that saw him suspended for six months by USA Swimming.
The ban interrupted the comeback which the 29-year-old had launched in 2014 that was aimed at the 2016 Rio Olympics.
"He's had a very good training cycle since he came back in November," said Phelps' coach Bob Bowman.
"The one thing he hasn't done is swim well in a meet yet.
"So, this is a great chance to do that. Any time now, I'm ready.
"But he's done the things to be able to swim well in a meet, and that's what's important.
"He's actually laid a foundation of training which, if he wants to get in his head and step on the gas tomorrow, he'll be ready to go."
Franklin is also gearing up for the global stage - next month's world meet and the Rio Games.
She already has four gold medals from the 2012 London Olympics but, after graduating from high school, opted to compete for two years for the University of California, before turning pro this year and inking a deal with Speedo.
The meet will be her only long-course competition before the World Championships.