Katie Ledecky will be anchoring the United States in the women's 4x100-meter freestyle relay.
Ledecky already swam in the afternoon preliminaries Saturday, leading the Americans to the second-fastest time behind the favored Australians.
She's the only holdover from the morning team. The U.S. rested its top two 100m free swimmers, Abbey Weitzeil and Simone Manuel, and they're also adding Dana Vollmer, who'll be doing double duty in the late-night session. She's also competing in the semifinals of the 100 butterfly, but we'll have more than an hour to rest up between races.
Manuel leads off for the Americans, followed by Weitzeil, Vollmer and Ledecky. They'll be trying to give the U.S. its first gold medal in the event since the 1996 Atlanta Games.
Defending Olympic champion Australia is a big favorite. Emma McKeon and Brittany Elmsie will take the top two legs, followed by sisters Bronte and Cate Campbell.