Michael Phelps was back in the pool Monday morning barely 13 hours after France rallied to beat the U.S. in the 400-meter freestyle relay with a surge in the last 50 meters.
Phelps had the fifth-fastest time in heats for the 200 butterfly, an event he has won in each of the last two Olympics.
Tyler Clary, the teammate who called out Phelps for his training habits, swam the second-fastest time behind Austria's Dinko Jukic.
Allison Schmitt and Missy Franklin were second and third behind world record holder and reigning Olympic champion Federica Pellegrini in heats for the women's 200 free.
Franklin, 17, will swim in the final of the women's 100 backstroke Monday night just 20 minutes after the semifinals of the 200 free.
"It's definitely going to be fun tonight," she said. "I need to try and keep my energy up as much as possible and do the best I can ... but it's going to be tough, for sure."
Monday night's most anticipated race is the men's 200-meter freestyle final with Ryan Lochte, 400 meter champion Sun Yang of China, South Korea's Park Tae-hwan and world record holder Paul Biedermann of Germany.
Yannick Agnel, who ran down Lochte to win the 400 freestyle relay Sunday night, is also in the field.
Matthew Grevers will swim in the 100-meter backstroke final in the evening after qualifying fastest while 2008 silver medalist Rebecca Soni and Breeja Larson give the U.S. a shot to medal in the women's 100-meter breaststroke.
Ye Shiwen had the fastest time in heats for the women's 200 individual medley while Kirsty Coventry was second. Americans Caitlin Leverenz and Ariana Kukors also made the semis.