MESA, Ariz. — Michael Phelps ended the first meet of his comeback on an odd note Friday, using his butterfly stroke to swim a 50-meter freestyle race that's never been part of his repertoire.
He was swimming to tinker with his form, not to win. And the race proved a side note to a week with greater implications for the record-setting Olympian and the sport he has loved since childhood.
Phelps' return sent a charge through what would have been a routine meet, and the shock waves will continue to ripple through the swimming world as long as he's around.
For the sport, Phelps is a signature star, capable of producing ticket sales, media attention and Olympic hype like no other.
For him, the comeback is both a source of joy and a potential marketing boon worth millions of additional dollars.
For swimming's rising talents, Phelps is like a living myth, a previously abstract standard of excellence who might now actually jump in the pool with them.
For old rivals, he's inspiration to get the competitive juices flowing for a few more years.
If Mesa is any evidence, world-class swimming is simply a more interesting neighborhood with Phelps in residence. And the path from here to the 2016 Olympics in Rio de Janeiro suddenly seems more exciting for everyone involved.
"Conventional wisdom would have had the road to Rio starting a year out, maybe 100 days," said Matt Farrell, chief marketing director for USA Swimming. "But his performance has just completely changed the definition and made it a different ballgame. He's the single most qualified person to make that happen."
Farrell said Phelps transcends the sport as an endorser of nonswimming companies such as Subway and Under Armour. His power on that front will only grow if he continues to swim at a high level.
The most interesting news might flow from the end of Phelps' career-long relationship with Speedo, the traditional 800-pound gorilla of competition swimwear.
"It's like imagining Tiger Woods outside of Nike," Farrell said.
He added that if Phelps signs with one of Speedo's competitors such as Arena or Tyr, it would be "an absolute game changer."
Could Under Armour, which already has a four-year relationship with Phelps, take this opportunity to dive into the swim market with him as the face of the initiative?
"That's a very interesting question," Farrell said. "It's not very common to see a new player come in and go to the highest level of the sport like that."
Phelps has only said he's a "free agent" in the swimwear market. But he didn't dismiss the Under Armour idea Friday and praised the company's CEO, Kevin Plank.
An Under Armour spokeswoman did not reply to a request for comment.
As much as he seemed to bask in the atmosphere he'd created, Phelps was the one person who didn't speak with certainty about his ongoing comeback. At least publicly, he continues to portray it as an open-ended exercise, one that will persist only as long as he's enjoying himself.
"It's one meet," he said when asked about Mesa's impact on his future thinking. "It's a long way, whether I decide to continue or not. This was awesome. I'm really excited about how things went. And I know what I need to do if I want to continue and want to swim faster."