The 45-year-old Torres finished fourth in the final of the 50-meter freestyle Monday night, her only event at the U.S. swimming trials.
After winning three silver medals at the Beijing Olympics, Torres underwent radical knee surgery and put all her hopes into one event.
But Jessica Hardy captured the one-lap sprint, touching in 24.50 seconds.
Kara Lynn Joyce took the other Olympic spot in 24.73, followed by Christine Magnuson (24.78) and Torres (24.82).
Torres lingered in the water after all the other swimmers had climbed out.
Then, she walked around the deck and scooped up her young daughter, who was wearing a green shirt that said “Go Mom.”