No need. His work was done. He had his 20th and 21st gold medals.
Phelps made up for one of the rare losses in his brilliant career by winning the 200-meter butterfly Tuesday night, a triumph that sent him climbing into the stands to kiss his 3-month-old son Boomer.
An hour later, he returned to take what amounted to nothing more than a triumphant victory lap in anchoring the 4x200 freestyle relay, the crowd's deafening roar growing louder with every stroke.
This was another performance for the ages, but Phelps has done it so many times that nothing else would have been fitting.
It came on a night that American teammate Katie Ledecky picked up her second gold of the Rio Olympics on the way to what could be a historic run of her own in the pool.
Phelps now has 25 medals in all, and three more races in Rio to add to his almost unimaginable total. The 200 fly was the one he really wanted, and it showed.
With challengers all around, Phelps simply wouldn't be denied. After touching the wall first by a mere four-hundredths of a second he held up one finger.
Then he sat on a lane rope, egging on the roaring crowd at the Olympic Aquatics Center with both hands, before emphatically pumping his fist.
Tears welled in his eyes during the medal ceremony until somebody in the crowd cracked him up. Then, during the customary stroll around the pool to pose for photographers, Phelps broke ranks and bounded into the stands to plant a kiss on Boomer, the son who symbolizes just how much Phelps' life has changed since a second drunken-driving arrest two years ago.
Phelps held off Japan's Masato Sakai with a time of 1 minute, 53.36 seconds, but that number was of little concern.
The only thing that mattered was getting to the wall first. Four years ago, Phelps mistimed his finish in the wind-milling stroke he does better than anyone, gliding to the wall a little too long after his final whirl of the arms.