MESA, Ariz. (AP) -- Michael Phelps' comeback meet was cut short Friday when he failed to advance to the 50-meter freestyle final.
The 18-time Olympic gold medalist used the morning preliminaries at the Arena Grand Prix to fine-tune his butterfly stroke instead of doing freestyle like everyone else. He finished seventh in a time of 24.06 seconds, missing out on the eight-man evening final.
Phelps didn't even make any of the three consolation finals because he was 42nd overall; only the top 32 qualify for those, so his first competition since retiring after the 2012 London Olympics ended early.
''I don't think there will be enough scratches,'' coach Bob Bowman joked about the possibility of Phelps getting into any of the finals.
Phelps ended up in the sprint because none of the day's other events - 400 individual medley, 200 freestyle and 200 backstroke - are ones that he plans to compete in during this comeback. He dominated the 400 IM during the height of career, but he vows he won't swim the grueling event anymore.
''I'm putting that out there: I am never swimming the 400 IM again,'' he said.
Bowman jabbed him, saying, ''Kind of like, 'I will never swim again.'''
At that, the longtime friends laughed.
Phelps had insisted he was done with swimming after London and frequently pointed out he had no intention of swimming past the age of 30. He turns 29 next month, and would be 31 by the time of the 2016 Rio Olympics.
Phelps tread lightly when pressed about his intentions toward a possible fifth Olympics. He was 15 at his first games in Sydney in 2000, when he was the youngest member of the entire U.S. team. He didn't medal, but went on to haul in 22 medals over his next four games, including a record eight gold in 2008.
He repeatedly emphasized he's having fun this time around and feels more relaxed than ever.
''I felt like a kid and that was the coolest part about it,'' he said. ''It's a good starting point, being able to get some races back under my belt.''
Phelps' goal Friday was to take just three breaths in the one-lap race; easy enough for a sprinter but not for a swimmer who specialized in distances ranging from 200 to 400 meters during his career.
''It's weird for me not to breathe,'' he said. ''I'm used to breathing every single stroke.''
He gulped air every second or third stroke, and halfway through he took two consecutive breaths.
''As soon as I did that, I was like, 'Man, I wonder if I can hold my breath the whole way,'' he said. ''I was like, 'No, I don't think so, so I snuck one more at 15.''
Afterward, Bowman told him, ''You don't really know how to swim a 50.''
Phelps replied, ''I guess that's a good thing.''
He finished second to Ryan Lochte in the 100 butterfly on Thursday, tying the fourth-fastest time in the world this year.
Next up for Phelps is high-altitude training in Colorado next month. He's entered in Grand Prix meets in North Carolina and California, although his presence hasn't been confirmed yet.
In the finals Friday, Lochte won the 200 freestyle in 1:49.48. Fellow Olympic gold medalists Nathan Adrian and Katie Ledecky also raced to their second victories in the meet. Ledecky won the women's 200 free in 1:56.27, and Adrian took the men's 50 free in 21.73.
Elizabeth Beisel won the women's 400 individual medley, Clara Smiddy took the women's 200 back, Russia's Arkady Vyatchanin won the men's 200 back, and Cheyenne Coffman topped the field in the women's 50 free.